Added test IOC for HDF5 XML layout.
Updated global switch to detector_data_destination and use ndattribute instead of value.
Added data switch record to the test IOC.
Setup test IOC to build under linux-x86_64 environment.
Improved XML error handling and fixed bug on file close.
Merge pull request #5 from ajgdls/hdf5_xml

Hdf5 xml. Fixing a number of small bugs and generally making the feature work.
Thanks Alan!