Let SettingsPage handle FontSelector and ColorButton automatically

Let SettingsPage handle FontSelector and ColorButton automatically

This means that SettingsPages can now handle both FontSelector and ColorButton automatically and
don't have to worry about tracking/saving/loading them. This should save us several hundred lines
of boilerplate code, and also some cute kittens.

I must reiterate that Qt's property system is worth a ton of bacon. At least.