add scaffold for `cvmfs_server tag`
add scaffold for `cvmfs_server tag`

reneme/cvmfs,cvmfs/cvmfs,Gangbiao/cvmfs,cvmfs/cvmfs,djw8605/cvmfs,Gangbiao/cvmfs,cvmfs/cvmfs,MicBrain/cvmfs,cvmfs/cvmfs,djw8605/cvmfs,alhowaidi/cvmfsNDN,Moliholy/cvmfs,Moliholy/cvmfs,alhowaidi/cvmfsNDN,reneme/cvmfs,reneme/cvmfs,DrDaveD/cvmfs,MicBrain/cvmfs,Moliholy/cvmfs,DrDaveD/cvmfs,Gangbiao/cvmfs,djw8605/cvmfs,trshaffer/cvmfs,djw8605/cvmfs,alhowaidi/cvmfsNDN,Gangbiao/cvmfs,trshaffer/cvmfs,cvmfs/cvmfs,reneme/cvmfs,cvmfs-testing/cvmfs,DrDaveD/cvmfs,DrDaveD/cvmfs,MicBrain/cvmfs,cvmfs-testing/cvmfs,reneme/cvmfs,trshaffer/cvmfs,cvmfs-testing/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,cvmfs-testing/cvmfs,trshaffer/cvmfs,djw8605/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,MicBrain/cvmfs,alhowaidi/cvmfsNDN,MicBrain/cvmfs,Moliholy/cvmfs,Gangbiao/cvmfs,cvmfs-testing/cvmfs,DrDaveD/cvmfs,Moliholy/cvmfs,alhowaidi/cvmfsNDN,DrDaveD/cvmfs