[MERGE] Add new LockTimeout exception

[Ian Clatworthy]

Martin Pool wrote:
> While working on <https://bugs.launchpad.net/bzr/+bug/172392> Jono and I made
> some cleanups to how locks are handled.  It turned out that bug did not need to
> be fixed in bzrlib, but I think they are still worth merging.

bb:tweak

This looks fine. Some very minor tweaks would be nice during the merge
though.

> -        # for the duration of this server, no UI output is permitted.
> -        # note that this may cause problems with blackbox tests. This should
> -        # be changed with care though, as we dont want to use bandwidth sending
> +        # for the duration of this server, no UI output is permitted.  note
> +        # that this may cause problems with blackbox tests. This should be
> +        # changed with care though, as we dont want to use bandwidth sending

note -> Note
dont -> don't

> === modified file 'bzrlib/tests/test_commit.py'
> --- bzrlib/tests/test_commit.py	2008-03-17 04:38:59 +0000
> +++ bzrlib/tests/test_commit.py	2008-04-21 08:14:39 +0000
> @@ -30,7 +30,7 @@
>  from bzrlib.commit import Commit, NullCommitReporter
>  from bzrlib.config import BranchConfig
>  from bzrlib.errors import (PointlessCommit, BzrError, SigningFailed, 
> -                           LockContention)
> +        )

That lone ) on the line by itself isn't needed any more. I'd remove the
() altogether in this case.

Ian C.