Random UI things

[Dregu]

• Random UI fixes
• Expose update_state() to run the game logic really fast, maybe to skip forward in a TAS or double the game speed
• Add set_frametime() to change the target engine fps, capped by gpu/monitor/vsync/whatever still

-- skip hundun rise in a few seconds, simulating everything in between but not wasting time to render it
while state.time_level < 5000 do
  update_state()
end

-- run game at double speed, but keep timer at normal speed
set_callback(function()
  if not no_repeat then
    no_repeat = true
    update_state()
    state.time_level = state.time_level - 1
    state.time_total = state.time_total - 1
    no_repeat = nil
  end
end, ON.POST_UPDATE)

-- run at 50% speed by changing frametime
set_frametime(1/30)

-- don't cap fps when window is unfocused
set_frametime_unfocused(0)