Fix circular dependency, make timeline column watchers less expensive
Rename timeline column directive
Add unit tests for timeline column data directive
Fix css class assignment after date changes in timeline comparisons
Fix change-indicating css classes in timeline comparison view
Restore former tl comparison markup (but donate an extra span tag)
Fix css classes indicating changed dates in timeline
Merge pull request #1241 from opf/fix/timeline-comparison-7256

Fix/timeline comparison 7256