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)

why is this done in makeEGTaus!

It should be done in makeTaus, what is happening to the electrons then?