GridFTP server ported from arc0 svn tree. This service can act as a secure
gateway to grid resources, providing authentication and authorisation through
several mechanisms. 3 plugins are provided by ARC:

- jobplugin (in a-rex/grid-manager/jobplugin) allows job submission,
  monitoring and control through the GridFTP interface
  
- fileplugin exposes a file-system hierarchy through the GridFTP interface

The plugins can be enabled through configuration described in the manual
"The NorduGrid Grid Manager and GridFTP Server"
