Rename JetIdParams_cfi.py to puJetIdParams_cfi.py.

This avoids name conflict on OSX due to case insensitive file system
there.
Merge pull request #3458 from ktf/fix-capitalization

Macosx -- Wrong capitalization.
Merge remote branch 'origin/CMSSW_7_1_X' into CMSSW_7_0_X