Added TARGET, MPIDIR, and BUILDDIR macro variables.
Added TARGET, MPIDIR, and BUILDDIR macro variables.

git-svn-id: http://svn.code.sf.net/p/petavision/code/sandbox@2254 7c0444ca-5550-0410-9008-faecdbe78eb5

Former-commit-id: d884c54848c7e7e94a266b86e0fde1ebfcac0482
dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,PetaVision/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV