Provide an option to reset view settings to the defaults

[hogsy]

Minor; right now if you change the view settings, save them and open again, obviously you're stuck with whatever you've set, but sometimes it might be helpful to reset them to the default which currently isn't possible unless I delete my config (which isn't super user-friendly, and I'll lose other things besides just the view settings).

I'd figure this should be an option at the bottom of the view menu.