1. Disabling of 'chdir($HOME)' in  'rootd' when running in Castor mode; this is
   because $HOME  may  point to a directory not available  on the servers.
2. A few optimizations in the Globus authentication:
   1. remove strong dependence on the user certificate on the client machine
      (all the information is retrieved from the proxy, if existing; if not, the
      certificate is looked for)
   2. one-time initialization of the server credentials
   3. separate root path for libs and incs; needed because some installations,
      e.g. lcg/external, are non standard.
   4. A number fixes of the coding conventions (lower case for local variables)
      and of code simplifications
3. A couple of bug fixes in rpdutils.cxx found by testing these changes


git-svn-id: http://root.cern.ch/svn/root/trunk@18245 27541ba8-7e3a-0410-8455-c3a389f83636