git-cms-init: use $CMSSW_GIT_HASH instead of $CMSSW_VERSION, if available
git-cms-showtags: use $CMSSW_GIT_HASH instead of $CMSSW_VERSION, if available
git-cms-checkdeps: use $CMSSW_GIT_HASH instead of $CMSSW_VERSION, if available
Merge pull request #59 from fwyzard/init_use_CMSSW_GIT_HASH

git-cms-init: use $CMSSW_GIT_HASH instead of $CMSSW_VERSION, if available