Fixing the reading of xAOD::TrigPassBitsContainer from 'problematic files' (xAODTriggerAthenaPool-00-00-25)

	* Added a custom POOL converter for xAOD::TrigPassBitsContainer.
	  Which fixes the incorrect containers created by ROOT from older
	  files. (Which were written without using a collection proxy
	  for this container.)
	* Cleaned the CMakeLists.txt file slightly.
	* Tagging as xAODTriggerAthenaPool-00-00-25