* OSD bugfix: write operations no longer cause an OSD crash

* new MRC:
  - added periodic volume info updates at DIR
  - added functionality to create XML dumps of the database (restoring dumps is still to do)
  - marginal bugfixes
* misc: made shell scripts in servers/bin work again

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@86 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534