rewrite: Restructure to include GUI.

src/settings/__init__.py

@@ -0,0 +1,7 @@
+from babel.translator import LocalBabel
+babel = LocalBabel('settings_base')
+
+from .data import ModelData, ListData
+from .base import BaseSetting
+from .ui import SettingWidget, InteractiveSetting
+from .groups import SettingDotDict, SettingGroup, ModelSettings, ModelSetting