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

[Alexander Belchenko]

Martin (gzlist) пишет:
> I welcome feedback on the larger design questions for a followup
> patch, but would like to see this version merged promptly so there can
> be some testing on a wider range of windows systems, and in a full
> range of scenarios involving plugins and so on.

bb:resubmit

This version does not pass tests for locks.
See `bzr --no-plugins selftest -s bt.per_lock` output.