/elec/propeller-clock

* Automatically draw text.

  Text::draw() should be called from propeller-clock.cc, and it should itterate

  over active messages and call draw_message() on them (which does what the

  current draw() does).

  This requires that Text somehow knows which messages are active. Perhaps

  message_reset() could somehow be used to determine this?

  This is necessary so that the cludgy call to Text::post_draw() can be removed

  from propeller-clock.cc. The problem here is that if _do_draw_reset is set

  false inside what is currently Text::draw(), only the first drawn message is

  ever correctly reset!

  This would also make calls to Text::draw() unnecessary from mode draw()

  routines.

  At the same time, remove calls to Text::reset() from SwitcherMajorMode. This

  now be done at the start of reset_messages(), which should be renamed to

  set_up_messages() in all modes.

* Restore call to Button::set_press_mode()

  This was removed when switching to mode classes. But how to restore it?

  The button could be "passed" to the SettingsMajorMode, so that it can set and

  unset interim presses on activation/deactivation?