Ported to Rails 4.
Sorted out Rails 4 deprecation warnings.
Removed auto-completion functionality.

Autocompletion of lemmata in the morphology annotation editor broke on
the update to Rails 4. As this code is ripe for an update to take
advantage of modern JS, this patch disables the functionality for now
and removes the obsolete and broken code.
Monkey-patch the audited gem to make model attributes accessible.