Django v1.6: full django-denorm compatibility
Using quote_name for all field names.

Some fields need this (particularly those with lower and upper case
or those that otherwise would be reserved keywords).

Along the way, connection's using 'using' was normalized to be
consistently used and passed around where it was needed.
DirtyInstance model has unique together (content_type, object_id)
Added support for swapped models
Optimizations for denorm_rebuild and denorm_flush (less database hits)