.arcconfig

ssh: unban the use of pipe character in user@host:port string

This vulnerability was fixed by the previous patch and there were more ways
to exploit than using '|shellcmd'. So it doesn't make sense to reject only
pipe character.

Test cases are updated to actually try to exploit the bug. As the SSH bridge
of git/svn subrepos are not managed by our code, the tests for non-hg subrepos
are just removed.

This may be folded into the original patches.

{
    "conduit_uri": "https://phab.mercurial-scm.org/api",
    "repository.callsign": "HG",
    "arc.land.onto.default": "@",
    "base": "hg:.^"
}