The time KCM backend code is quite old and is somewhat buggy because
toggling any option causes all fields to update. I cleaned up the code
and isolated different options from each other, and ensured the QML UI
bindings stay up to date. I also moved the date popup to a loader so
that it isn't loaded at start.
Having the KCMs that are mobile specific here makes more sense than in the settings application. Historically plasma-settings had a faster release cycle than Plasma, but the application is now moving to the Plasma release schedule and so it makes sense do this now.
