- establish make_transient and make_transient_to_detached as special-use,
advanced use only functions
- list all conditions under make_transient() under which an attribute
will not be loaded and establish that make_transient() does not attempt
to load all attributes before detaching the object from its
session, fixes #3640

(cherry picked from commit 7eff4e8f3e3999d9eb914647d8776e6e5b7ee88e)

where we refer to the "weak_identity_map" option, and add additional
exposition in the session documentation which refers to it.
fixes #3517

(cherry picked from commit 956907a4b15f6dcc492582a7ad03706ff62d96fb)

Conflicts:
	lib/sqlalchemy/orm/identity.py

(cherry picked from commit 51870ddaef8abf61ee4c8d6337a72db5395a0a85)

:meth:`.Session.begin_nested` operations would fail to propagate
the "dirty" flag for an object that had been updated within
the inner savepoint, such that if the enclosing savepoint were
rolled back, the object would not be part of the state that was
expired and therefore reverted to its database state.
fixes #3352

(cherry picked from commit 359f471a1203cafd5dc99b5b078ba7d788b67cec)

an ``after_rollback()`` handler for a :class:`.Session` incorrectly
adds state to that :class:`.Session` within the handler, and the task
to warn and remove this state (established by :ticket:`2389`) attempts
to proceed.
fixes #3309

(cherry picked from commit ad66266d3d275a6129e3270eaacdad171bc10817)

with :meth:`.Connection.execution_options` when a :class:`.Transaction`
is in play; DBAPIs and/or SQLAlchemy dialects such as psycopg2,
MySQLdb may implicitly rollback or commit the transaction, or
not change the setting til next transaction, so this is never safe.
- Added new parameter :paramref:`.Session.connection.execution_options`
which may be used to set up execution options on a :class:`.Connection`
when it is first checked out, before the transaction has begun.
This is used to set up options such as isolation level on the
connection before the transaction starts.
- added new documentation section
detailing best practices for setting transaction isolation with
sessions.
fixes #3296

(cherry picked from commit 9cbe235810b7c0c24d2556b4bb581b0207812e2d)

Conflicts:
	test/orm/test_bind.py

to :meth:`.Session.close`, except also calls
:meth:`.Connection.invalidate`
on all connections, guaranteeing that they will not be returned to
the connection pool.  This is useful in situations e.g. dealing
with gevent timeouts when it is not safe to use the connection further,
even for rollbacks.
references #3258

(cherry picked from commit cf7981f60d485f17465f44c6ff651ae283ade377)

session, and refer to InstanceState.session.  Add note about
objects that are deleted within an ongoing transaction.

sqlalchemy/orm, sqlalchemy/event, sqlalchemy/testing

Conflicts:
	lib/sqlalchemy/dialects/mssql/base.py
	lib/sqlalchemy/dialects/mysql/base.py
	lib/sqlalchemy/dialects/mysql/mysqldb.py
	lib/sqlalchemy/dialects/oracle/base.py
	lib/sqlalchemy/dialects/sybase/base.py
	lib/sqlalchemy/orm/attributes.py
	lib/sqlalchemy/orm/evaluator.py
	lib/sqlalchemy/orm/identity.py
	lib/sqlalchemy/orm/instrumentation.py
	lib/sqlalchemy/orm/loading.py
	lib/sqlalchemy/orm/mapper.py
	lib/sqlalchemy/orm/session.py
	lib/sqlalchemy/orm/sync.py
	lib/sqlalchemy/sql/compiler.py
	lib/sqlalchemy/sql/selectable.py
	lib/sqlalchemy/testing/requirements.py
	lib/sqlalchemy/testing/suite/test_select.py