Turned back on G_IB.  Use G_IB for AHP.  Removed resetting of G_E and G_I on firing.
Turned back on G_IB.  Use G_IB for AHP.  Removed resetting of G_E and G_I on firing.

git-svn-id: 602a26e73ae9f2a14e2bb95676f2e137fcc39919@2319 7c0444ca-5550-0410-9008-faecdbe78eb5

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