mergetools.hgrc: add minimal configuration for editmerge

The ``editmerge`` script is shipped in contrib and opens an editor on
every conflicting file. It needs minimal configuration to inject the
config marker in the file before opening. Otherwise it behaves the
same as ``internal:local`` and bad things happen.
tests: better tests for two-way convert
convert: rename sink hascommit to hascommitforsplicemap

The name 'hascommit' sounds like something generic ... but it might
also throw exceptions in specific cases and it is thus (apparently)
only useful for splicemap.
convert: introduce hascommitfrommap sink method

Mercurial has stable revision identifiers and rollback and strip. Revisions
referenced in the shamap are thus not necessarily still present but we can
easily check for it.

Subversion do not have stable identifiers and no rollback or strip(?). We must
thus assume that all revisions referenced from a shamap still must be present.

This method is similar to hascommitforsplicemap but different ...
convert: only consider shamap revisions converted if they still exists

Rollback or strip could leave a Mercurial repo with a shamap with revisions no
longer in the repository.

To ensure reliable conversions we now check that the commit actually exists and
consider it non-existing if it doesn't exist.
fix_bytes: loosen blacklist matching requirements

On my Linux machine, paths seen by 2to3 include the build directory. We
switch from an exact to substring match to allow 2to3 to work in more
environments.
buildrpm: various minor cleanup
buildrpm: collect code for building local hg and using it in one place
buildrpm: remove prompt for uncommitted changes - it was a bad idea

We want a command that is useful in scripts, not an interactive command.

--HG--
extra : amend_source : 1fb377098b039c47eddbd09cda4ec3289c5f9951
buildrpm: include release version in .tar.gz name

Official releases are fully indentified by the version number, these builds are
not.

Specs are however traditionally not versioned.

--HG--
extra : rebase_source : ef8aefdf9313e508cb07ff838c71a6a9baa1e3bb
docker: check for docker.io first

--HG--
extra : rebase_source : 7854f68fb95ac4f8cb1e5b7da7092f5de773a3e0