Updates to 7.0.X: electron ids, mc matching, fix multiloop

Includes #78 and partially addresses #63 by adding cut-based electron ids (the ones presented by Giovanni Zevi using the full5x5 shower shapes, and for completeness also the run 1 ones both on new and old shower shapes) and computing the MVA id both with new shower shapes and old full5x5 ones.
Also, updates the ttH gen-level analyzer and MC matcher so that it works in pythia 8 (though more effort is needed to make it more general, and cover some corner cases)