add test cases for double fork switch
add test cases for double fork switch

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