Added documentation about interaction between `subqueryload` and LIMIT/OFFSET.
add update() support to MutableDict
fix MutableDict.coerce

If a class inherited from MutableDict (say, for instance, to add an update() method), coerce() would give back an instance of MutableDict instead of an instance of the derived class.
Added support for postgres_relkind.
Merge branch 'master' of https://github.com/rclmenezes/sqlalchemy
Add a view synonym too for consistency.
- proof of concept
dev
- change to be represented as two very fast bulk_insert() and bulk_update() methods
- refine this enough so that _collect_insert_commands() seems
to be more than twice as fast now (.039 vs. .091); bulk_insert()
and bulk_update() do their own collection but now both call into
_emit_insert_statements() / _emit_update_statements(); the approach
seems to have no impact on insert speed, still .85 for the
insert test
Merge branch 'master' into ticket_3100

Conflicts:
	lib/sqlalchemy/orm/mapper.py
	lib/sqlalchemy/orm/persistence.py
dev
dev
- refinements
Merge branch 'master' into ticket_3100
- rename mapper._primary_key_props to mapper._identity_key_props
- ensure bulk update is using all PK cols for all tables
Merge branch 'master' into ticket_3100
Merge branch 'master' into ticket_3100
- skip these methods
- test for postfetch->sync.populate() having importance during an UPDATE
at the per-table level