incoming: use a subquery for Check.ordinal instead of a separate query

models: drop Check.raw field (not worth storing in the same table) Replaying checks can be done (and is easier) when storing checker output in plain files, so let's lighten up the load on the database.

incoming: strip linebreaks from lines before storing them

incoming: mark "job failed" line as a failure

tests: test another regex in incoming (luacheck-style linter output)

incoming: make initial state = None

incoming: use named groups in start-of-the-string regex

linters: jshint config

checker: configurable allowed exit codes for linters

linters: luacheck config