add class version
Add tags_in_gts command to the migration script
Merge pull request #2911 from ojeda/migrate-script-tags-in-gt

CondCore/Utilities -- Add tags_in_gts command to the migration script
Merge pull request #2901 from VinInn/VersionedCandidate

Misc fixes -- Add class version for Candidate.
Merge remote branch 'origin/CMSSW_7_1_X' into CMSSW_7_0_X