sparse routine for computing xcorr, doesn't use fft and doesn't save individual xcorr for each pair, only mass-xcorr and peak and average power for individual pairs
sparse routine for computing xcorr, doesn't use fft and doesn't save individual
xcorr for each pair, only mass-xcorr and peak and average power for individual pairs

git-svn-id: 602a26e73ae9f2a14e2bb95676f2e137fcc39919@2661 7c0444ca-5550-0410-9008-faecdbe78eb5

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