An UPDATE emitted as a result of the
:paramref:`.relationship.post_update` feature will now integrate with
the versioning feature to both bump the version id of the row as well
as assert that the existing version number was matched.

Fixes: #3496
Change-Id: I865405dd6069f1c1e3b0d27a4980e9374e059f97

1. Section decorators to [one style](http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#sections):
without inset at both side and with same length as text.
2. Fix broken [reference](http://docs.sqlalchemy.org/en/latest/core/type_basics.html#generic-types).
3. Convert tabs to space in some small files.
4. Some python code snippets have python+sql syntax hint.

Change-Id: I39a7a41ef0b0591c6bf1e610748e2b5c19fc5379
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/361

Adding a new kind of relationship loader that is
a cross between the "immediateload" and the "subquery"
eager loader, using an IN criteria to load related items
in bulk immediately after the lead query result is loaded.

Change-Id: If13713fba9b465865aef8fd50b5b6b977fe3ef7d
Fixes: #3944

1.2 wip

Change-Id: I0a3c4a0166f6feed23a021723233d281fad597ec

Change-Id: I88a304e315b68eded31e91da04265da583bc417b

Added warnings to the LRU "compiled cache" used by the :class:`.Mapper`
(and ultimately will be for other ORM-based LRU caches) such that
when the cache starts hitting its size limits, the application will
emit a warning that this is a performance-degrading situation that
may require attention.   The LRU caches can reach their size limits
primarily if an application is making use of an unbounded number
of :class:`.Engine` objects, which is an antipattern.  Otherwise,
this may suggest an issue that should be brought to the SQLAlchemy
developer's attention.

Additionally, adjusted the test_memusage algorithm again as the
previous one could still allow a growing memory size to be missed.

Change-Id: I020d1ceafb7a08f6addfa990a1e7acd09f933240

Some updates for FAQ/Performance documentation page:

* Fix typo in testing script.
* Populate testing script with one more way to achieve higher performance.

See commit messages for details.

Change-Id: Id6fbf328164b14b3b58ca9616b103a35e72f7b8f
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/345

The longstanding behavior of the :meth:`.Operators.in_` and
:meth:`.Operators.not_in_` operators emitting a warning when
the right-hand condition is an empty sequence has been revised;
a new flag :paramref:`.create_engine.empty_in_strategy` allows an
empty "IN" expression to generate a simple boolean expression, or
to invoke the previous behavior of dis-equating the expression to
itself, with or without a warning.  The default behavior is now
to emit the simple boolean expression, allowing an empty IN to
be evaulated without any performance penalty.

Change-Id: I65cc37f2d7cf65a59bf217136c42fee446929352
Fixes: #3907