[dev] Extension of commentCallback

[duck]

Now commentCallback call passes only the title of the commented data. 
But is completely natural to allow moderation of the comments to the 
user who actually owns the commented data.

I purpose to extend the standard commentCallback call with a second 
parameter specifying the type of data to be retrieved. When doing a 
classic comment, the title will be retrieved. But when creating a new 
forum (for comments), we can retrieve the data owner so we can delegate 
edit/delete permissions to the owner. So he can automatically have the 
possibility to manage offensive content under its photo albums and so on.

Duck