ng2-1.0.0-alpha.4: Uncaught (in promise): TransitionRejection

Chrome (and ng2 polyfills) log an error to the console if a promise is rejected, but there was no .catch() attached.

This is causing problems in ng2 because the reject factory is doing this:
`new Promise((resolve, reject) => reject(foo)` instead of `Promise.reject(foo)`.
