is_locked optimization

[tridge at samba.org]

Jeremy,

 > As expected, I have a Win32 test run using two different processes
 > accessing the same file using oplocks - the byte range locks and reads
 > are not seen on the wire. Turning off oplocks - the locks and reads
 > are seen again.
 > 
 > I think this is a safe option (but maybe not default).

ok, sounds good, and sorry for doubting you :-)

Can you also send me the win32 prog? It could be a useful base for
other tests.

Cheers, Tridge