Added queryset-like functionality to 'as_of' manager method
Removed 'get_user_model' usage in admin.py on import
Update docstring
Simplified `as_of` logic, handle non-id pk fields
Double check for deleted items since history_date can match
Test for multiple objects for class-based `as_of`
Fix line length
Merge pull request #106 from treyhunner/non-instance-as-of

Extend the 'as_of' method to work as a class method
Added initial 'compare view' work
Removed use of 'render_to_response' from admin
Cleanup, refactor logic
Added test to access compare view
Fix admin compatability-related coverage
Added coverage for delta helper method
Compatability fixes
Removed Django 1.3 from the test matrix
Fixed line length
Added Python 3.4 to the matrix, bumped tested Django versions
Use HhtmlDiff to generate the diff table
Removed unused custom delta sequence generator