Previously, with --config resolve.mark-check=abort, running hg resolve -m foo
would abort and emit a message saying to use --all. This command does not work,
though: hg resolve -m foo --all, and it's really weird for --all to be the
"--force" flag.
My original goal with the option was to make it so that hg resolve -m (no
filename arguments) was safer, which is why --all is used; in my mind, `hg
resolve -m foo` should always mark it as resolved, and --all is how you
specify "all the files", so that's why I chose hg resolve -m --all as the way
out of hg resolve -m aborting. This commit makes all of this work the way it
was meant to in my head :)