settings: Consolidate RangedSetting's with regular ones

The latest git version of GCC has issues with my diamond inheritance
shenanigans. Since that's now two compilers that don't like it I thought
it'd be best to just axe all of it and just have the two templates like
before.

This rolls the features of BasicRangedSetting into BasicSetting, and
likewise RangedSetting into Setting. It also renames them from
BasicSetting and Setting to Setting and SwitchableSetting respectively.
Now longer name corresponds to more complex thing.