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
Added the templatetags package to the list of project packages
Simple output check for `diff_table` templatetag
Allow historical tracking to be set on abstract bases
Handle non-abstract inheritance
Merge branch 'historical-abstract-base'
Fixed merge conflicts with compare-history.
Merged cherry-pick conflict with m2m field support.