Revert "mds: rip out rename linkmerge support"
Revert "mds: rip out rename linkmerge support"

This reverts commit d467fbfd1714ef04faf41e604d6a78e33ef7fa10.

The linkmerge stuff _is_ needed for reintegrating multi-linked stray
inodes back into the hierarchy.  E.g.,

 touch a
 ln a b
 rm a

The MDS will want to renamed the stray inode to the b dentry.

Conflicts:

	src/mds/Server.cc

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@newdream.net>

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph