[MERGE] Implement bzrlib.lock with CreateFile rather than LockFileEx on win32 (operational part)

[Martin (gzlist)]

2009/6/19 Martin Pool <mbp at canonical.com>:
> Martin Pool has voted approve.
> Status is now: Semi-approved
> Comment:
> OK, it doesn't actually break unix.

Yeah, sorry, is just a bit of cruft deletion left over from my
previous more comprehensive clean up. One of those duplicated
constants wasn't even the right case. :)

> It should be mentioned in NEWS, including whether this makes it any faster
> or more robust, or is just cleaner.

I considered a NEWS entry just after committing, felt writing
"(Hopefully) invisible change to implementation details of locking on
win32" would be a little strange. Expect the performance to be
basically the same, as runtime should be dominated by touching the
filesystem - have done some simple testing now that roughly confirms
that.

> I'd like to hear from Alexander or another win32 expert before merging it.

As would I, particularly for some testing on non-en-locale windows.

Martin