first implementation with Eigen
adapt to inclusion of eigen as an external
optimizations for symmetric matrices and avoiding the use of std set
further optimizations and fixes, plus consistent uncertainty calculation with optimized code
bring setting of OOT energy back in line with latest changes and silence printout
make uncalib rechit producer multithreaded
remove no longer needed code
cleanup debug printouts
Merge pull request #5321 from bendavid/ecalMultifit_optimized

Ecal multifit optimized