using a column key of the form ``<tablename>_<columnname>``
matching that of an aliased column in the text would still not
match at the ORM level, which is ultimately due to a core
column-matching issue.  Additional rules have been added so that the
column ``_label`` is taken into account when working with a
:class:`.TextAsFrom` construct or with literal columns.
[ticket:2932]

would fail if the referred table in a foreign key contained a schema
name.  Pull request courtesy Thomas Farvour. pullreq github:67

constructs would fail if the bind were constructed with a callable,
rather than a direct value.  This prevented ORM expressions
from being rendered with the "literal_binds" compiler flag.

calling ``MyClass.attribute`` will not require that the configure
mappers step has occurred, e.g. it will just work without throwing
any error. [ticket:2935]

pymysql) from working in Py3K, where a check for "connection
charset" would fail due to Py3K's more strict value comparison
rules.  The call in question  wasn't taking the database
version into account in any case as the server version was
still None at that point, so the method overall has been
simplified to rely upon connection.character_set_name().
[ticket:2933]

"history" on a relationship-bound attribute will now no longer emit
any SQL if the relationship is unloaded.