discovery: adds a function doing revnum independant sorting The function is doing a topological sort without depending on revision number. This make the sort independent of the repository and suitable for discovery.

hgignore: also ignore the 'dist' directory This is generated by the 'sdist' command

obsexchange: drop unused module shame shame shame

MANIFEST.in: also includes topic That was also overlooked when we added topic.

MANIFEST.in: fix to include all evolve submodule This was overlooked before.

obsdiscovery: organize the code by category A private function get promoted to public since another module uses it.

evolution: drop the old __temporary__.advertiseobsolete option Mercurial code supports such feature directly though its 'experimental.evolution' config option. So we drop the old code and config.