Settings highlight

Part of #965

Display a blue dot next to setting that's different from default. Theme tab should only have one next to preset selector, also preset selector should specify which theme is the default one.

IGNORE THE "NEW" label, that will come in later, not part of this issue

This should help users recover from "what did I change" situations.

Should also remove the "(Default: yes)" labels

Dots should have either title attr or a small popover explaining that setting is different from default.