Use the new DLM operation callbacks while requesting new lockspace

Attempt to use the new DLM operations. If it is not supported,
use the traditional ocfs2_controld.

To exchange ocfs2 versioning, we use the LVB of the version dlm lock.
It first attempts to take the lock in EX mode (non-blocking). If
successful (which means it is the first mount), it writes the
version number and downconverts to PR lock. If it is unsuccessful,
it reads the version from the lock.

If this becomes the standard (with o2cb as well), it could
simplify userspace tools to check if the filesystem is mounted
on other nodes.

Dan: Since ocfs2_protocol_version are two u8 values, the additional
checks with LONG* don't make sense.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>