Update state.changeHead to new syntax
Fire state events from StateChange

Otherwise calling a redo can never trigger events - which e.g. broke
down redo in the dependencyTree

Works on #323
Minor refactor in state.change()
Fix a typo in state
Fix StateChange specs
Remove tokens in batch mode

because they can lead to follow up changes.
Don't redraw the tree on tokenAdded

... led to an ugly screen flickering.
Fix undoing of tokenRemoved
Merge pull request #346 from latin-language-toolkit/undo_redo_fixes

Undo/redo fixes
Add a default value for the language flag
Capture nil for relation in TreebankRetriever

... and blank it, so as not to distort the unused counts.
Add .bold css class
Allow to specify a empty-val for valueWatch

... used in dependencyTree to highlight unset values better.
Add bold class for empty valueWatch values
Merge pull request #347 from latin-language-toolkit/relation_nils

Updates to valueWatch (relation label styling) and relation label parsing
Animate nested dropdowns for usability

Code taken from http://www.greywyvern.com/?post=337#.
Minor: Cleanup
Use mixins for dropdown visibilty
Adjust animation values