Update CephFS to work on Hadoop 2.x

This is more an RFC if anything, we are currently, probably insanely, using ceph as a cornerstone of our infrastructure at $DAYJOB

These changes appear to be what is needed to make the filesystem work on top of hadoop 2.x 

Thoughts ? Comments ?

I want to poke ceph itself and see if we can get the java blobs into maven repos ...