fix help message
fix for when CMSSW_GIT_REFERENCE is not set
use git cms-init to setup the local repository, and do not try to change TAG when adding a package
properly silence/unsilence messages from git clone and git fetch
use git cms-init to setup the local repository
remove the temporary file after the checkout
drop unused -f/--force option
make the -d/--debug option actually work
Merge pull request #34 from fwyzard/master

simplify the logic of git-cms-addpkg, plus varous minor bug fixes