Removes tabs controls

They've been deprecated for a while and I haven't noticed an outcry.
Merge pull request #1683 from trek/remove-tabs-control

Removes tabs controls
App.container was not meant to be a public API

It appears that people are starting to use
App.container.lookup as the public API for
globally getting other controllers outside of the
router or other controllers.

This was not intended to be a public API.

Instead, you should trigger events on a route
(or a parent route), which have access to
`this.controllerFor`.

Example:

    App.ApplicationRoute.extend({
      events: {
        search: function(term) {
          this.controllerFor('search')
            .set('term', term);
        }
      }
    });

    App.SearchField = Ember.TextField.extend({
      insertNewline: function() {
        var term = this.get('value'),
            controller = this.get('controller');

        controller.send('search', term);
        this.set('value', '');
      }
    });

Events sent to the controller will bubble up to
the current route, and then up the route hierarchy
Provide a precompilation package

This should make it easier to maintain external
precompilers without stubbing out parts of Ember
Correct spelling of 'already' in assertion.
Merge pull request #1686 from topfunky/spelling/already

Correct spelling of 'already' in assertion.
More useful debug name for generated controllers