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
Yes, chi squared values are always positive, and all alternate chi square values are always >= chisq0 by construction.  (This is basically a MINOS uncertainty scan evaluated with two points, so the chisq away from the minimum is always larger than the minimum)