Additional hlt integrations post frozen version for steam

This pull request allow in the Run2 HLT menu the paths from the following JIRA tickets:

CMSHLT-150: High multiplicity trigger for low-PU runs
CMSHLT-151: EXO Monojets (in master table an GRun)
CMSHLT-161: Electron + HT cross trigger (in mster table only)
CMSHLT-165: Integration of moderate pt lepton + hadronic suite
CMSHLT-166: Photon + HT path for SUSY (in master table an GRun)
CMSHLT-167; Double Lepton + HT triggers for SUSY (in mster table only)

Further: cleanup explicit GT payloads, and a few fixes and cleanings here and there