discovery: use stable sort order in --new-branch warning
A Python set seems to do this already when you iterate over it, but
this should be considered an implementation detail and not something
we can rely on.
This also gets rid of an unnecessary string conversion -- the set
already contains strings.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.