status: add a config knob for setting default of --terse I want --terse=u basically 100% of the time, but there's not a good way to do that before this patch. I'm very unhappy with how the default value for --terse looks rigt now, but it does *work*. The alternative would be to define an "optional string" flag type using fancyopts.customopt and then use that, leaving the default as None. Does anyone have a strong preference for that, or a better idea? Differential Revision: https://phab.mercurial-scm.org/D3627