revert: fix(closure): add Closure externs for angular.$q.Promise.finally

This reverts commit caeb7402651702cd13df2f1594e9827439a8b760.

The commit breaks Google apps because most don't use closure compiler
with the ES5 mode flag on. We are investigating a solution...
Merge branch 'master' of https://github.com/angular/angular.js
componentizd!