puffs - status report 6

[Tatsiana Severyna]

Progress:
- ported psshfs (puffs sshfs). Man page states it's buggy, so I didn't
spent much time on it. It just works in simplest workloads
- ported librefuse (fuse api wrapper library). It needs more work as
none of fuse filesystems I've tries worked correctly
- added fuse sshfs and unionfs to simplify testing
- fixed remaining statfs and vptofh/fhtovp issues