Added the ability to synchronize XRF detectors to AMBeamline.  Right now, only adding and removing regions of interest are synchronized, but soon the bounding ranges will be sync'ed too.  There is a possibility to have all important aspects of the XRF detector settings sync'ed together, but for now, it will be minimalistic.
Fixed a bug in AMProcessVariableDataSource that wasn't returning the appropriate values for array's when not asking for the whole array.  Fixed a small size bug in AMRegionOfInterestAB.