Revert "Merge pull request #2577 from machty/bubbling-controller-events"

This reverts commit 05686ccce26808da4a1e1247b131c68cfba15486, reversing
changes made to 7387d6723b5a20395dfd041a67633a6101c2259d.

This changed introduced a regression in #2636 and should be reverted until we can decide on a better/safer API. Note that we're preserving the bubbling function provided in router.js for event handlers in the `events` hash, which is far more important than bubbling within the controller.

The root of the regression is as follows: if you put `{{action toggleProperty 'foo'}}` in your template (a hack to some, sugar to others, but suggested in the docs at http://emberjs.com/guides/controllers/), the `action` helper will use `.send`, which will bubble if the result of the called function is true, and since `toggleProperty` returns true half the time, the event will bubble half the time.