Fix kernel panic when invoking fuse_purge_np

HNodeLookupRealQuickIfExists tries to unlock biglock even though it has not
been locked.

Stack trace of the panic:

    fuse_purge_np
    ...
    fuse_device_ioctl
    HNodeLookupRealQuickIfExists
    fusefs_recursive_lock_unlock

Reported by megrimes@socket.net
Actively wait for user space daemon to complete FUSE_INIT handshake

If the FUSE_INIT handshake is not completed by the user space daemon within
deamon_timeout mark the file system as dead. This makes sure processes
accessing an uninitialized FUSE file system are not being blocked indefinitely
while waiting for the potentially dead user space daemon to complete the
handshake.
Remove unused mount-time option init_timeout
Merge branch 'osxfuse-2'

Conflicts:
	fuse_nodehash.c