[python][patch] Add temporary breakpoint features to Python breakpoints.

[Tom Tromey]

Tom> Is there a PR associated with this?
Tom> I thought there was, but I didn't check.

Phil> I did a search and I could not find one.

Thanks.  I was thinking of the pending support.

Phil> Other nits fixed up too.  ChangeLog remains the same.

Phil> OK?

This is ok.  Thanks.

Tom