libxtreemfs: yet another interrupt mechanism...

Everything is migrated to use fuse_interrupted.
Options now maintains deprecated options and has a mechanism to create warnings when they are used.
Some testing/review is needed.

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@3142 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534