Added new param to plotWeights, now the function can sort by activity if data is provided.
Added new param to plotWeights, now the function can sort by activity if data is provided.

git-svn-id: 602a26e73ae9f2a14e2bb95676f2e137fcc39919@9508 7c0444ca-5550-0410-9008-faecdbe78eb5

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