Always make sure choices get cleaned up when building results.

Because ``this.choices_count`` was getting called after
``@selected_option_count = null``, this condition NEVER passed.
The prototype js didn't get committed? Weird.
Merge pull request #1286 from harvesthq/fix-choice-build-after-update

Fix choice build after update
Merge branch 'master' into fix-disabled-multi-chosen

Conflicts:
	public/chosen.jquery.min.js
	public/chosen.proto.min.js