New Ecal Local Reconstruction with Multifit

Adds additional EcalUncalibRecHitWorker for MultiFit (using Fast NNLS algorithm) and modifies appropriate sequences to activate it by default.

@argiro @emanueledimarco
Also,  xplus100-x0 is just _errvec[ipulseintime] isn't it? I am wondering if you need the extra manipulation and if _errvec[ipulseintime]  could be zero (you divide by it few lines below).