introduce NominalCollision2015 beamspot scenario, according to: https://indico.cern.ch/event/341218/
beamspot of postLs1 relvals set to NominalCollision2015; run1 relvals left as they were, making it explicit Realistic8TeVCollision (note: Realistic8TeVCollision is still the cmsDriver default)
UNDO: beamspot of postLs1 relvals set to NominalCollision2015
Added L1Menu_Collisions2015_25ns_v1_L1T_Scales_20101224_Imp0_0x102f.xml
and the corresponding customization.
HLT update with new menu but before L1 update
Restore v2 part
Fix TSG integration test script
finish resizing legacy collections to make packer happy
add l1t 2015 to post LS1 customizations
Turn on new L1 menu.
add missing import
Reverted to using the legacy CPE error
Merge remote-tracking branch 'official-cmssw/CMSSW_7_2_X' into revertNewCPE

Conflicts:
	RecoLocalTracker/SiStripRecHitConverter/python/StripCPEfromTrackAngle_cfi.py
HLT update for new L1
Fix addOn tests with PostLS1 custom and data/repack
Fix REPACK step in TSG tests
HLT menu fixes and extraction fixes
Fix up special treatment for HIon data
fix for insidious bug that skips function declarations in an extern C context if their name does not contain an _ in the last position.
Fix Integration Test Script