libxtreemfs: Changed interface to used byte arrays instead of ReusableBuffers....

libxtreemfs: Changed interface to used byte arrays instead of ReusableBuffers. Fixed two bugs in write operation / stripe translation.

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@2923 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534