tools: fixed a bug in the MRC dump/restore tool that could cause bogus...

tools: fixed a bug in the MRC dump/restore tool that could cause bogus X-Locations lists to be assigned to files being restored from a dump, improved output in case of failures

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@1215 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534