Dynamically add new editions to albums
Update to rails 4.0.0
Simplify another.js by using the add link's data attributes
Allow an album to destroy its associated editions
Dynamically add track fields to tracklists

another.js was cleaned up to avoid naming collisions.
Build track's first translation
Show track numbers on tracklist form

another.js callbacks now get passed `this` as the first argument.
Format duration on tracklist form