Changes from IValeriu's Branch
This checking Prepares for changes wich will follow.
There ar no functional changes, If you look into the modfied Files, ther are only new Methods, so this Commit will not break anything!
Also the Generic Dataprovider is implemented
Jointure Extension fixes from Ivaleriu's branch...
-  Linq support
-  Some bugs were fixed on JointureAddon which permit now more complex associations