topic: add a simple option to reject publishing The option is pretty basic but it can be used as base to build larger feature. The main target for going in this direction is to be able to distinct between user that are "simple contributors" pushing topic for review and the "maintainers" or "automation" that can publish changesets.

compat: adjust `wrapadd` for upstream Mercurial core updated the API in f385ba70e4af.

debian: override default value for SPHINXBUILD in docs/makefile This is the recommended Debian approach. As suggested by Debian Developer Stephen Kitt, use the approach recommended by Debian for building Sphinx documentation. See https://wiki.debian.org/Python/LibraryStyleGuide#Sphinx_documentation Also belated credit to Zash on the #mercurial channel on the Freenode IRC network, who suggested the Make variable approach in the first place.

obshashtree: move obshashtree in its own module The code no longer serve a core purpose. We just keep it because the command might be useful. We move it in a dedicated module so that it does not get in the way of other work.