Fixes with multiple joins and A->B->C joins.

JOIN: Added join tests & fixed bugs with join.

This turned up some faults when you wanted to Query C From A through a B join. So, if you specifically specified the FQ field name it failed, because the ORM attempted to prepend the self.class name.

Structure:
Person->Department->Location

Code example:
Person * p = [[[[[Person query]
joinTo:[Department class] leftParameter:@"department" targetParameter:@"Id"]
joinTo:[Location class] leftParameter:@"Department.location" targetParameter:@"Id"]
fetch]
firstObject];