git is used only if actually present
git is used only if actually present

At the same time:
   * references to git repo/branch in help message only if git is really
     available on machine;
   * actions are not counted, but actual vetos are implemented;
   * output on terminal about repo/branch used for git checkout;

SixTrack/SixDesk,SixTrack/SixDesk,SixTrack/SixDesk,SixTrack/SixDesk