- Eliminates code duplication in query cache patch
- Reduces the number of iterations in mysql-wsrep#201.test
  to shorten the execution time
- Adds a new test case that exercises more scenarios

- Fixes query cache so that it is aware of wsrep_sync_wait.
  Query cache would return (possibly stale) results to the
  client, regardless of the value of wsrep_sync_wait.
- Includes the test case that reproduced the issue.

Part 5: Removing calls to current_thd in net_read calls, creating fields,
        query_cache, acl and some other places where thd was available

The data base lenth passed to invalidator fixed

The reason for the failure was a bug in an include file on debian that causes 'struct stat'
to have different sized depending on the environment.

This patch fixes so that we always include my_global.h or my_config.h before we include any other files.

Other things:
- Removed #include <my_global.h> in some include files; Better to always do this at the top level to have as few
  "always-include-this-file-first' files as possible.
- Removed usage of some include files that where already included by my_global.h or by other files.


client/mysql_plugin.c:
  Use my_global.h first
client/mysqlslap.c:
  Remove duplicated include files
extra/comp_err.c:
  Remove duplicated include files
include/m_string.h:
  Remove duplicated include files
include/maria.h:
  Remove duplicated include files
libmysqld/emb_qcache.cc:
  Use my_global.h first
plugin/semisync/semisync.h:
  Use my_pthread.h first
sql/datadict.cc:
  Use my_global.h first
sql/debug_sync.cc:
  Use my_global.h first
sql/derror.cc:
  Use my_global.h first
sql/des_key_file.cc:
  Use my_global.h first
sql/discover.cc:
  Use my_global.h first
sql/event_data_objects.cc:
  Use my_global.h first
sql/event_db_repository.cc:
  Use my_global.h first
sql/event_parse_data.cc:
  Use my_global.h first
sql/event_queue.cc:
  Use my_global.h first
sql/event_scheduler.cc:
  Use my_global.h first
sql/events.cc:
  Use my_global.h first
sql/field.cc:
  Use my_global.h first
  Remove duplicated include files
sql/field_conv.cc:
  Use my_global.h first
sql/filesort.cc:
  Use my_global.h first
  Remove duplicated include files
sql/gstream.cc:
  Use my_global.h first
sql/ha_ndbcluster.cc:
  Use my_global.h first
sql/ha_ndbcluster_binlog.cc:
  Use my_global.h first
sql/ha_ndbcluster_cond.cc:
  Use my_global.h first
sql/ha_partition.cc:
  Use my_global.h first
sql/handler.cc:
  Use my_global.h first
sql/hash_filo.cc:
  Use my_global.h first
sql/hostname.cc:
  Use my_global.h first
sql/init.cc:
  Use my_global.h first
sql/item.cc:
  Use my_global.h first
sql/item_buff.cc:
  Use my_global.h first
sql/item_cmpfunc.cc:
  Use my_global.h first
sql/item_create.cc:
  Use my_global.h first
sql/item_geofunc.cc:
  Use my_global.h first
sql/item_inetfunc.cc:
  Use my_global.h first
sql/item_row.cc:
  Use my_global.h first
sql/item_strfunc.cc:
  Use my_global.h first
sql/item_subselect.cc:
  Use my_global.h first
sql/item_sum.cc:
  Use my_global.h first
sql/item_timefunc.cc:
  Use my_global.h first
sql/item_xmlfunc.cc:
  Use my_global.h first
sql/key.cc:
  Use my_global.h first
sql/lock.cc:
  Use my_global.h first
sql/log.cc:
  Use my_global.h first
sql/log_event.cc:
  Use my_global.h first
sql/log_event_old.cc:
  Use my_global.h first
sql/mf_iocache.cc:
  Use my_global.h first
sql/mysql_install_db.cc:
  Remove duplicated include files
sql/mysqld.cc:
  Remove duplicated include files
sql/net_serv.cc:
  Remove duplicated include files
sql/opt_range.cc:
  Use my_global.h first
sql/opt_subselect.cc:
  Use my_global.h first
sql/opt_sum.cc:
  Use my_global.h first
sql/parse_file.cc:
  Use my_global.h first
sql/partition_info.cc:
  Use my_global.h first
sql/procedure.cc:
  Use my_global.h first
sql/protocol.cc:
  Use my_global.h first
sql/records.cc:
  Use my_global.h first
sql/records.h:
  Don't include my_global.h
  Better to do this at the upper level
sql/repl_failsafe.cc:
  Use my_global.h first
sql/rpl_filter.cc:
  Use my_global.h first
sql/rpl_gtid.cc:
  Use my_global.h first
sql/rpl_handler.cc:
  Use my_global.h first
sql/rpl_injector.cc:
  Use my_global.h first
sql/rpl_record.cc:
  Use my_global.h first
sql/rpl_record_old.cc:
  Use my_global.h first
sql/rpl_reporting.cc:
  Use my_global.h first
sql/rpl_rli.cc:
  Use my_global.h first
sql/rpl_tblmap.cc:
  Use my_global.h first
sql/rpl_utility.cc:
  Use my_global.h first
sql/set_var.cc:
  Added comment
sql/slave.cc:
  Use my_global.h first
sql/sp.cc:
  Use my_global.h first
sql/sp_cache.cc:
  Use my_global.h first
sql/sp_head.cc:
  Use my_global.h first
sql/sp_pcontext.cc:
  Use my_global.h first
sql/sp_rcontext.cc:
  Use my_global.h first
sql/spatial.cc:
  Use my_global.h first
sql/sql_acl.cc:
  Use my_global.h first
sql/sql_admin.cc:
  Use my_global.h first
sql/sql_analyse.cc:
  Use my_global.h first
sql/sql_audit.cc:
  Use my_global.h first
sql/sql_base.cc:
  Use my_global.h first
sql/sql_binlog.cc:
  Use my_global.h first
sql/sql_bootstrap.cc:
  Use my_global.h first
  Use my_global.h first
sql/sql_cache.cc:
  Use my_global.h first
sql/sql_class.cc:
  Use my_global.h first
sql/sql_client.cc:
  Use my_global.h first
sql/sql_connect.cc:
  Use my_global.h first
sql/sql_crypt.cc:
  Use my_global.h first
sql/sql_cursor.cc:
  Use my_global.h first
sql/sql_db.cc:
  Use my_global.h first
sql/sql_delete.cc:
  Use my_global.h first
sql/sql_derived.cc:
  Use my_global.h first
sql/sql_do.cc:
  Use my_global.h first
sql/sql_error.cc:
  Use my_global.h first
sql/sql_explain.cc:
  Use my_global.h first
sql/sql_expression_cache.cc:
  Use my_global.h first
sql/sql_handler.cc:
  Use my_global.h first
sql/sql_help.cc:
  Use my_global.h first
sql/sql_insert.cc:
  Use my_global.h first
sql/sql_lex.cc:
  Use my_global.h first
sql/sql_load.cc:
  Use my_global.h first
sql/sql_locale.cc:
  Use my_global.h first
sql/sql_manager.cc:
  Use my_global.h first
sql/sql_parse.cc:
  Use my_global.h first
sql/sql_partition.cc:
  Use my_global.h first
sql/sql_plugin.cc:
  Added comment
sql/sql_prepare.cc:
  Use my_global.h first
sql/sql_priv.h:
  Added error if we use this before including my_global.h
  This check is here becasue so many files includes sql_priv.h first.
sql/sql_profile.cc:
  Use my_global.h first
sql/sql_reload.cc:
  Use my_global.h first
sql/sql_rename.cc:
  Use my_global.h first
sql/sql_repl.cc:
  Use my_global.h first
sql/sql_select.cc:
  Use my_global.h first
sql/sql_servers.cc:
  Use my_global.h first
sql/sql_show.cc:
  Added comment
sql/sql_signal.cc:
  Use my_global.h first
sql/sql_statistics.cc:
  Use my_global.h first
sql/sql_table.cc:
  Use my_global.h first
sql/sql_tablespace.cc:
  Use my_global.h first
sql/sql_test.cc:
  Use my_global.h first
sql/sql_time.cc:
  Use my_global.h first
sql/sql_trigger.cc:
  Use my_global.h first
sql/sql_udf.cc:
  Use my_global.h first
sql/sql_union.cc:
  Use my_global.h first
sql/sql_update.cc:
  Use my_global.h first
sql/sql_view.cc:
  Use my_global.h first
sql/sys_vars.cc:
  Added comment
sql/table.cc:
  Use my_global.h first
sql/thr_malloc.cc:
  Use my_global.h first
sql/transaction.cc:
  Use my_global.h first
sql/uniques.cc:
  Use my_global.h first
sql/unireg.cc:
  Use my_global.h first
sql/unireg.h:
  Removed inclusion of my_global.h
storage/archive/ha_archive.cc:
  Added comment
storage/blackhole/ha_blackhole.cc:
  Use my_global.h first
storage/csv/ha_tina.cc:
  Use my_global.h first
storage/csv/transparent_file.cc:
  Use my_global.h first
storage/federated/ha_federated.cc:
  Use my_global.h first
storage/federatedx/federatedx_io.cc:
  Use my_global.h first
storage/federatedx/federatedx_io_mysql.cc:
  Use my_global.h first
storage/federatedx/federatedx_io_null.cc:
  Use my_global.h first
storage/federatedx/federatedx_txn.cc:
  Use my_global.h first
storage/heap/ha_heap.cc:
  Use my_global.h first
storage/innobase/handler/handler0alter.cc:
  Use my_global.h first
storage/maria/ha_maria.cc:
  Use my_global.h first
storage/maria/unittest/ma_maria_log_cleanup.c:
  Remove duplicated include files
storage/maria/unittest/test_file.c:
  Added comment
storage/myisam/ha_myisam.cc:
  Move sql_plugin.h first as this includes my_global.h
storage/myisammrg/ha_myisammrg.cc:
  Use my_global.h first
storage/oqgraph/oqgraph_thunk.cc:
  Use my_config.h and my_global.h first
  One could not include my_global.h before oqgraph_thunk.h (don't know why)
storage/spider/ha_spider.cc:
  Use my_global.h first
storage/spider/hs_client/config.cpp:
  Use my_global.h first
storage/spider/hs_client/escape.cpp:
  Use my_global.h first
storage/spider/hs_client/fatal.cpp:
  Use my_global.h first
storage/spider/hs_client/hstcpcli.cpp:
  Use my_global.h first
storage/spider/hs_client/socket.cpp:
  Use my_global.h first
storage/spider/hs_client/string_util.cpp:
  Use my_global.h first
storage/spider/spd_conn.cc:
  Use my_global.h first
storage/spider/spd_copy_tables.cc:
  Use my_global.h first
storage/spider/spd_db_conn.cc:
  Use my_global.h first
storage/spider/spd_db_handlersocket.cc:
  Use my_global.h first
storage/spider/spd_db_mysql.cc:
  Use my_global.h first
storage/spider/spd_db_oracle.cc:
  Use my_global.h first
storage/spider/spd_direct_sql.cc:
  Use my_global.h first
storage/spider/spd_i_s.cc:
  Use my_global.h first
storage/spider/spd_malloc.cc:
  Use my_global.h first
storage/spider/spd_param.cc:
  Use my_global.h first
storage/spider/spd_ping_table.cc:
  Use my_global.h first
storage/spider/spd_sys_table.cc:
  Use my_global.h first
storage/spider/spd_table.cc:
  Use my_global.h first
storage/spider/spd_trx.cc:
  Use my_global.h first
storage/xtradb/handler/handler0alter.cc:
  Use my_global.h first
storage/xtradb/handler/i_s.cc:
  Use my_global.h first

* remove incorrect assertion (it didn't take into account concurrent clients)
* fix the comment