Updated to use a pickled file if root_numpy is unavailable. We need to get David's computer working nicely. Need to generate a readme of good installation instructions to get numpy, scipy, matplotlib, root_numpy, root, rootpy, all working nicely with each other. it'snot hard. but it's not easy. Two functions added. showEvents() which shows up to  events, default is set at 25. computeEfficiency() which computes the efficiency.