Fixes and updates to the HLT Run2 menu, other will follow

The following fixes have been integrated in the HLT menu:
- Changing thresholds for HLT_AK8PFHT850_TrimR0p1PT0p03Mass50, CMSHLT-179
- Changing pt cuts of muon + photon trigger, CMSHLT-182
- Update of the dielectron path, CMSHLT-183
- Modify prescales (now 1) in EXO photon trigges, CMSHLT185
- Corrected alpha-T triggers, CMSHLT-187