Stop project sites and catalogues from standing for unrelated repositories master
- repourl: catalogue sites (Octave Forge, the Octave package index, PEAR, homalg) name no repository; Octave Forge's per-package repositories are keyed separately; python.org subdomains other than CPython's own give PyPI entries or PyPy; gnupg.org project pages no longer hint at GnuPG; opendev.org is a Gitea forge. - distro: host rules for gnupg.org projects and PyPy releases; docs.xfce.org maps only a project's own page; a direct registry entry is kept as a candidate. - bulk: a candidate supported only by a project site decides a package only when the package is named like the repository; a repository cited in a PyPI description counts only when named like the project; OpenStack's GitHub mirrors map to opendev.org; registry aliases are recomputed in full. - lookup, compare and export open the database read-only.