adding a removeMessage method
adding a mNotification attribute to TTCallback class to change notification sensivity (default : kTTSym_notify)
adding kTTSym_notification symbol to the cache
Using specific notifications inside Schedulers instead of using kTTSym_notify now TTCallback can change their notification sensitivity
Using only one SchedulerTicked notification to pass the progression and treal time values to observers
Merge branch 'dev' of github.com:jamoma/JamomaCore into dev