finished the last function in MGS: mgs_steal_llog_for_mdt_from_client.

finished the last function in MGS: mgs_steal_llog_for_mdt_from_client.
compilation passed.
mgs_steal_llog_for_mdt_from_client has the following steps:
	1. find a "marker" to identify the start of adding osc/mdc for clients;
	2. duplicate config log from clients' to mdt's:
		(a) add start marker;
		(b) duplicate add_uuid;
		(c) duplicate attach, modify uuid for the new obd;
		(d) duplicate setup;
		(e) duplicate lov_add to lov_add (or lmv_add to cmm_add);
		(f) add end marker;
	3. got a "marker" to end. goto 1. to find another.