adapt IoDispatcher to new Reader API
adapt IoDispatcher to new Reader API

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