fix(mobile-ng-click): prevent unwanted opening of the soft keyboard

Ghost clicks are busted but the corresponding form elements are still focused. This means that for example on smartphones the soft keyboard will be opened. This pull request prevents the unwanted opening of the soft keyboard.
fix($parse): unwrap promise when setting a field

This fixes an inconsistency where you can't call the setter function
when the expression resolves to a top level field name on a promise.

Setting a field on an unresolved promise will throw an exception.  (This
shouldn't really happen in your template/js code and points to a
programming error.)

Closes #1827
fix(re-bootstrap): Throw an error when bootstrapping a bootstrapped element.

Nothing would prevent a user from accidentally calling angular.bootstrap on an element that had already been bootstrapped. If this was done, odd behavior could manifest in an application, causing different scopes to update the same DOM, and causing debugger confusion.

This fix adds a check inside of angular.bootstrap to check if the passed-in element already contains a class of ng-scope, and if so, will throw an error.