Return const & to avoid making a copy
Remove not needed cleaning of newly created collection
Remove not needed cleaning of collection to be destroyed at the end of the loop
Make tokens private class members
migrate cout to MessageLogger
moving to more efficient operator[], which should be safe here
Merge pull request #6713 from mbluj/multithreadFriendly_forTauTrg_74X

Code cleaning
Merge remote branch 'origin/CMSSW_7_4_X' into CMSSW_7_0_X