* Add an explicit configuration option for stars
* Replace now-outdated "left handed" widgets config option, now that
select widgets are always on the left.
* since the multi-modality of the message list was now only a "toggle
stars" option, kill that, as it was lots of code and rather redundant
global config option rather than a per-account one. (But with a new
implementation.) - As we now have views that show messages across
accounts, this needed to become a global)
