added compiler directives for easier implementation of special cases
added compiler directives for easier implementation of special cases

git-svn-id: http://svn.code.sf.net/p/petavision/code/sandbox@3423 7c0444ca-5550-0410-9008-faecdbe78eb5

Former-commit-id: 0eaba8f2b50ad12839128ef2d1aa254aa8084ee0
dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV