Change the key for objects to their name.

Change the key for objects to their name.
Support "--lmv <lmvname>" for CMD.  Using --lmv is how LMVs were built with
lmc in 1.4 and since we are trying to source lmc, we should simply use the
same syntax.
find_obj()->find_objs() now returns all objects that match.
So callers need to expect lists and deal with them.  In a lot of cases a
caller can *know* that the list returned will be only one item if the lmc
file is contructed correctly.
Support specification of multiple MDTs on the same MDS using different
devices.
For this, the mountpoint of the MDT needs to use the fsname to make it
unique.
The MDTs and OSTs also need to be created with fsnames.
Use the --node <name> from the lmc mtpt object as the fsname.