Fixed reversion admin for django 1.4
InlineAdminFormSet has a different `__init__` in Django 1.4

It now takes a `prepopulated_fields` argument, accessible from
`ModelAdmin.get_prepopulated_fields`.
Increment supported Django version for django-1.4 branch
Adding support for multiple db
Made modifications to multi-db support to be a bit more consistent throughout the API to encourage use of the 'db' through out instead of depending on the model private state. Although there are two exceptions to this when using signals, since we don't control how our API gets called here.

Also added a check for nested revision context managers to make sure consistent use of db is used.
Found a way around peeking into the model state for multi-db support. yay!

Also (removing some pudb cruft). Ooops!
Merge branch 'master' into django-1.4
Throwing RegistrationError if VersionAdmin is used with a proxy model.

Fixes https://github.com/etianen/django-reversion/issues/102
Merge git://github.com/eliast/django-reversion
Refactoring multi-db support to use set_db and get_db methods.
Decoupling model db and reversion db in get_deleted method
Merge pull request #122 from fusionbox/master

Allow object pks to have slashes in them
Merge branch 'multi-db'
Separing out do_revert into a separate helper function called
safe_revert. Fixes #83.
Merge branch 'master' into django-1.4
Fixing error in parent revision recovery.
Possible fix for #104
Merge branch 'master' into django-1.4
Adding in fix for issue #128 - tests (CreateInitialRevisionsTest and
VersionAdminTest) failing
Merge branch 'master' into django-1.4