Minor code cleanup based on actual use
Renamed CachedProducts to TriggerResultsBasedEventSelector which better describes its purpose
TriggerResultsBasedEventSelector now uses EventPrincipal directly so we do not have to make a temporary edm::Event
Moved function out of OutputModule header and source files in order to reuse elsewhere.
Made SubProcess no longer inherit from edm::OutputModule. This was accomplished by moving common code to different class files
Removed unnecessary include of CachedProducts.h specifically because that file is now gone
Merge pull request #188 from Dr15Jones/subProcessNotOutputModule

SubProcess no longer an OutputModule