The settings GameCube Controller N and Wii Remote N (where N is a number)
have two purposes: You can select what controller type you want to use,
and also, when you select a controller type (even if you're selecting the
one that already is selected), the mapping settings open. This second part
is less discoverable than it ideally should be. I'm changing it so that
there now is a button for opening the mapping settings instead.

It was a bit silly having four functions for effectively the same thing
in all of SettingsFragmentView, SettingsFragment, SettingsActivityView,
SettingsActivity, and SettingsActivityPresenter.

With this change, we split on the four MenuTag types in
SettingsActivityPresenter instead of in SettingsAdapter.

Also removed the make_sure_continuous_scan_enabled message.
It doesn't make sense with the new UX.