Branch b1_4

Branch b1_4
Description: doing an ls when liblustre clients are running is slow
Details    : sending a glimpse AST to a liblustre client waits for every AST
	     to time out, as liblustre clients will not respond while they
	     are processing.  Since they cannot cache data anyways we refresh
	     the OST lock LVB from disk instead.
b=7198
r=phil, green (original patch)