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
Is it guaranteed that  chisqplus100-chisq0 is always positive (are matrix manipulations  inside ComputeChiSq()  always returning a positive value?)?