* new MRC: added support for deleting volumes, adding/removing replicas,...

* new MRC: added support for deleting volumes, adding/removing replicas, changing file owners/groups, and setting extended attributes

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@45 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534