New TCastorFile: a TCastorFile is like a normal TNetFile except that it

obtains the remote node (disk server) via the CASTOR API, once the
disk server and the local file path are determined, the file will be
accessed via the rootd daemon. File names have to be specified like:
    castor:/castor/cern.ch/user/r/rdm/bla.root
The patch level of libshift should be at least 1.5.x (which is the one
installed on all CERN machines in /usr/local).
The CASTOR HSM interface code is provided by Jean-Damien Durand of the
CASTOR team.


git-svn-id: http://root.cern.ch/svn/root/trunk@7310 27541ba8-7e3a-0410-8455-c3a389f83636