add new performance measurement tool (CondCore/Utilities/bin/conddb_test_gt_perf.cpp) with related updates

move to use tbb parallel_for_each instead of boost threadpool
Merge branch 'CMSSW_7_1_BOOSTIO_X' of https://github.com/cms-sw/cmssw into apfeiffer1/ap-cond-perf
Merge pull request #2515 from apfeiffer1/ap-cond-perf-rebase

update for 7.1.BOOSTIO branch