Merge pull request #924 from smuzaffar/IB/CMSSW_7_0_X/stable

from 53X: added support for default compiler and extra tools
fastjet-contrib: Backport fastjet-contrib from CMSSW_7_2_X
Merge pull request #943 from nclopezo/backport-fasjet-contrib-to-70x

fastjet-contrib: Backport fastjet-contrib from CMSSW_7_2_X
scram-project-build: sync changes from 72x/71X in to 70X