Merge pull request #47 from ttyS15/master

An option for database dependent cache keys
Use `db_agnostic` cache profile option instead of fidelity

NOTE: db_agnostic=True means fidelity=False (default)
Cleaned up tests for `db_agnostic` cache profile option
Documented `db_agnostic` option
Fix import error in Django 1.7
Fix AttributeError in Django 1.6
Better error message when unable to stringify queryset
Fixed another imcompatability with Django 1.7
Fix a typo
Merge pull request #50 from streeter/patch-1

Fix a typo
Added invalidate object benchmark
Merge branch 'master' of github.com:Suor/django-cacheops
Added save_obj bench
Updated CHANGELOG
Upped to 1.0.3
Remove Django 1.7 deprecation warnings
Fix cache_on_save in newer Djangos
Invalidation on old state on newer Djangos
Minor refactoring and optimization
Updated CHANGELOG