Decouples edit comment view controller

Fixes #2260 

@aerych || @diegoreymendez: Gentleman, may i bother you with a review?.

Thank you!
Just a note on naming - I realize this can be very subjective.

1. `editCommentViewController: didUpdateComment:` doesn't necessarily sound like you should dismiss the editor.
2. `editCommentViewControllerWasDismissed` sounds like the editor was dismissed already.

One alternative (still subjetive, bear with me 😬) could be to unify both delegate methods into something like:

`-(void)editCommentViewController:(EditCommentViewController *)sender finishedWithUpdates:(BOOL)hasUpdates`?