client:

- Log error message instead of assert() if file handles are left when the volume gets closed.
- Removed unnecessary occurrences of xtreemfs::util as "using namespace" is in effect.

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@2725 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534