Add select2 3.5.2
Reference select2 styles in asset pipeline
select2 and bootstrap should play nicely together
BulkTagger prettifies tags

* Required now Select2 submits ugly compact tag lists (e.g. 'this,that,other').
Make mapping tag feature read consistently
Parse tags into Select2 multi-value
Eschew ids in favour of classes for the tag list hooks
Ensure "," breaks to create a new tag
Set up autocompleteWith for tags on client side