Makefile for unit tests directory.  You can compile the tests with or without OpenCL, using "make opencl=1 all" or "make opencl=0 all".  The default is opencl=1.
Makefile for unit tests directory.  You can compile the tests with or without OpenCL, using "make opencl=1 all" or "make opencl=0 all".  The default is opencl=1.

git-svn-id: 602a26e73ae9f2a14e2bb95676f2e137fcc39919@4508 7c0444ca-5550-0410-9008-faecdbe78eb5

dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV