Hook some events directly on the directive component.

- afb:like directive now supports on-edge-created and on-edge-removed events.
- afb:comments directive now supports on-comments-created and on-comments-removed events.
- Adding afb:send directive. The message.send event is currently implemented but I don't know why it don't get fired after sending a message.
- Resolving some issues on the unit testing.
1.0.3