added new decfiles for B2KDarkBoson2hh analysis

add decay files for B -> K DarkBoson, DarkBoson -> hh, have requested for hh = KK and hh = pipi. have requested for a variety of DarkBoson lifetimes and masses. lifetimes chosen s.t. we have LL tracks. masses chosen taking into account limits ... min mass:hh pair at rest (560/988 MeV) and max mass: B rest mass (5.279 GeV) minus K rest mass (0.494 GeV). only generator cuts which are applied are eta cuts made on final state particles to ensure inside lhcb acceptance (have used slightly wider than acceptance to account for reco issues). Analysis is run2 hence should work with sim09 and sim10.