Rename sticky library to show we are using a modified version

Requested that the accepted pull request be released as a new version:
https://github.com/alexmingoia/sticky/pull/18#issuecomment-44092006
Remove semicolons from coffeescript
Use Backbone.$ instead of $ directly

See https://github.com/nilbus/Backbone.dualStorage/pull/73#issuecomment-42846039
Clarify a comment with ambiguous meaning
syncDirtyAndDestroyed resolves with the results from both
Only expose the promise for each deferred we create

This way only we can resolve or fail it.
Use => over -> only where necessary
Return early from syncDirtyOrDestroyed if dirty

Avoids looking up destroyed when not necessary.
Rename variable to convey its final purpose
Remove debug variable assignment