ENH: localize prefs dialog
ENH: localize Coder-demo-submenu names

- Builder demos are probably best left as is
FF: localize 'Field' and 'Default' labels in the Preference Dialog
TEST: update Japanese translation
Merge branch 'feature-localization' of https://github.com/jeremygray/psychopy into feature-localization
ENH: localize items in Preference Dialog, Coder menu and Static component
ENH: enable better translation of "set during:"