Added additional parameter to emitting events, if action already occured...

Hey Damien! 

I've added new parameter to events, which are emitted. The parameter says if action already occurred:
* if user already liked the document
* already removed like from document
* already liked a comment
* already removed like from comment
* already removed comment

I've added this because it made mess in my code when listener function was executed and the event didn't really happen. You know what I mean?

Thanks
Matus