It might be a good idea to offer some support for auto in _config.yml, but issue a deprecation warning if it's used. We can remove it at 1.1, once everyone's accustomed to watch.
+1 good idea.
Unlike the previous set of CL options, there is presently no --no-watch switch. Might be a good idea to add this in before we convert auto values.
Backwards-compatibility for 'auto'. Fixes #821.