Repoint ForeignKeys when their to= changes.
Add M2M repointing
Add check constraint support - needed a few Field changes
Merge branch 'master' into schema-alteration
Very initial Oracle support
Stubbed-out oracle schema file
Fix app loading/test interaction
Merge remote-tracking branch 'core/master' into schema-alteration

Conflicts:
	django/db/backends/mysql/base.py
	django/db/backends/postgresql_psycopg2/base.py
More schema test fixing
Fix bug in get_indexes affecting the tests
Python 3 compatability. 2.6 was a while back, I should learn ' as '.
Stylistic fixes: triple-quoted docstrings, more comments
Dropping pointless self.fail calls
Un-borg-ify AppCache
Remove AppCache state handling, replace with swappable caches
Remove special-casing for proxy/unmanaged models
Remove weird syncdb managed thing - no longer needed.
Fix introspection PK comment more.
Fix non-executed SQL
Do cheaper check for column having a type.