Model class associated to comments db table
Added 'comments' and 'commentCount' relations
Changed base class from CActiveRecord to TrackStarActiveRecord
Renamed 'createUser' relation to 'author'
Added single quote to cles string value related to 'commentCount' relation
Comment CRUD files
Added 'addComment' method for asigning issue id to an instance of 'Comment' class
Changed 'actionView' method in order to pass an instance of 'Comment' class to the view