rebase: avoid redundant merges (
issue1301)
Make contrib/buildrpm work on Fedora 9.
mercurial.spec had bitrotted. These changes makes it possible to build an rpm that is usable.
Only minimal changes has been made, and there is plenty of room for improvement.
help: Refine a bit the help text of "hg update"
Parts of the original text were submitted by Hubert Kauker (Hubert
dot Kauker at travelbasys.de). This is a slightly revised version
of Hubert's original text.