misc: replace domain of mercurial ML address by mercurial-scm.org This patch also adds new check-code.py pattern to detect invalid usage of "mercurial@selenic.com". Change for test-convert-tla.t is tested, but similar change for almost same test-convert-baz.t isn't yet tested actually, because I couldn't find out the way to get "GNU Arch baz client". AFAIK, buildbot skips test-convert-baz.t, too. Does anybody have appropriate environment for testing?