Added feedback to loading a saved game and made controller input leave the save and load screens just like mouse input does.
Added prompt to confirm starting a new game when you already have a team.
Added a better interface for overscan adjustments.  Still need an actual adjustment screen.
Added overscan adjust screen when ENABLE_OVERSCAN_ADJUST is defined.
Added saving and loading of overscan setting via save_settings() and load_settings().  The same file will probably be used to fully replace the old config file later.