DeviceData ctor bug.

Fix bug in DeviceData ctor. Do not use the ApiUtil::get_orb() call to test if the ORB ptr is nil. It increments the ORB ref. counter (due to use of duplicate CORBA call) which was not decremented. This was the reason of this ref counter reaching enormous value and even in some cases becoming negative (it is one int in omniORB code) which could lead to a process crash ! Create a new method in ApiUtil class to test if the ORB is nil.