Don't write to a temporary file, use String.
Remove strange one-liner "helpers", use String methods.
Don't use current_thd, don't allocate memory for 1-byte strings, etc.

- It turns out, ha_rocksdb::table_flags() can return
  HA_PRIMARY_KEY_IN_READ_INDEX for all kinds of tables (as its meaning
  is "if there is a PK, PK columns contribute to the secondary index
  tuple". There is no assumption that a certain PK column can be decoded
  from the secondary index.
  (Should probably be fixed in the upstream, too, but I was unable to
   construct a testcase showing this is necessary).

- Following the above, we can undo the init_with_fields() changes in
  table.cc. MyRocks calls init_with_fields() from ha_rocksdb::open()
  which sets index-only read capabilities properly.

and a few trivial test result updates

This cset just re-uses the approach from facebook/mysql-5.6 (Perhaps we
will have something different for MariaDB in the end).

For now this is:
Port this fix
  dd7eeae69503cb8ab6ddc8fd9e2fef451cc31a32
  Issue#250: MyRocks/Innodb different output from query with order by on table with index and decimal type
  Summary:
  Make open_binary_frm() set TABLE_SHARE::primary_key before it computes

Also add the patch for
  https://github.com/facebook/mysql-5.6/issues/376

* remove a confusing method name - Field::set_default_expression()
* remove handler::register_columns_for_write()
* rename stuff
* add asserts
* remove unlikely unlikely
* remove redundant if() conditions
* fix mark_unsupported_function() to report the most important violation
* don't scan vfield list for default values (vfields don't have defaults)
* move handling for DROP CONSTRAINT IF EXIST where it belongs
* don't protect engines from Alter_inplace_info::ALTER_ADD_CONSTRAINT
* comments

MDEV-10134 Add full support for DEFAULT

- Added support for using tables with MySQL 5.7 virtual fields,
  including MySQL 5.7 syntax
- Better error messages also for old cases
- CREATE ... SELECT now also updates timestamp columns
- Blob can now have default values
- Added new system variable "check_constraint_checks", to turn of
  CHECK constraint checking if needed.
- Removed some engine independent tests in suite vcol to only test myisam
- Moved some tests from 'include' to 't'. Should some day be done for all tests.
- FRM version increased to 11 if one uses virtual fields or constraints
- Changed to use a bitmap to check if a field has got a value, instead of
  setting HAS_EXPLICIT_VALUE bit in field flags
- Expressions can now be up to 65K in total
- Ensure we are not refering to uninitialized fields when handling virtual fields or defaults
- Changed check_vcol_func_processor() to return a bitmap of used types
- Had to change some functions that calculated cached value in fix_fields to do
  this in val() or getdate() instead.
- store_now_in_TIME() now takes a THD argument
- fill_record() now updates default values
- Add a lookahead for NOT NULL, to be able to handle DEFAULT 1+1 NOT NULL
- Automatically generate a name for constraints that doesn't have a name
- Added support for ALTER TABLE DROP CONSTRAINT
- Ensure that partition functions register virtual fields used. This fixes
  some bugs when using virtual fields in a partitioning function

remove:
* NDB from everywhere
* IM from mtr-v1
* packaging/rpm-oel and packaging/rpm-uln
* few unused spec files
* plug.in file
* .bzrignore