Begin changes to support proxy models.
Proxy model support by following concrete model
update README.rst for desription of fork.
Update README.rst
Update setup.py
Add support for generic signals

This is achieved by adding a keyword (signals) to register. This accepts
a list-like item containing signals to connect to. Some special-casing
was added to handle pre_delete. The default is still to just connect to post_save.
Also follow relationships immediately on pre_delete
hash using copied objects when processing pre_delete
Allow the user to decide whether a signal should be treated as eager
Make register api more intuitive
Don't try to loop over None
Merge https://github.com/AgDude/django-reversion
Merge remote-tracking branch 'remotes/upstream/master'

Conflicts:
	src/reversion/admin.py
	src/reversion/revisions.py
Add registration test
Add proxy model tests
Fix broken merge
Merge pull request #363 from bourivouh/master

Proxy model support
Removing deprecation warnings (fixes #360).
Merge pull request #365 from narrowfail/master

Removing deprecation warnings (fixes #360).
Unregister a model from all signals
Forgot to add _signals on __init__