remove many thread_local
factor 2 less
factor 2 less
factor 2 less
remove many thread_local
Merge pull request #4327 from ktf/backport-tls-fixes

Backport TLS fixes from #4293 to CMSSW_7_1_X
Merge remote branch 'origin/CMSSW_7_1_X' into CMSSW_7_0_X