Check if debug logs exist before compressing them
Merge pull request #927 from nclopezo/compile-fwlite-osx

scram-project-build: Check if debug logs exist before compressing them
Merge remote-tracking branch 'origin/IB/CMSSW_7_1_X/stable' into IB/CMSSW_7_0_X/stable
Merge remote-tracking branch 'origin/IB/CMSSW_7_2_X/stable' into IB/CMSSW_7_0_X/stable