Uct2015 core

@mcepeda @isobelojalvo 

Added tau veto cut within uct producer. Introduced a variable in emulation_cfi to control the pt threshold where the veto cut is switched off. This required reconstructing some of the loops that I had previously written in order to further differentiate 4x4 vs 4x8 taus (tau veto cut cannot be applied for 4x4 taus)

Ok, rereading you have modified both makeEGTaus and makeTaus. Ok. 

I think we should have renamed makeEGTaus to makeEG and removed any tau reference from there (a bit too late now with the emulator comissioned and running)