In SDL, support HWSURFACE by drawing to lcd_get_frame directly.
Also support DOUBLEBUF with two buffers, one simply using lcd_get_frame, and
another malloced surface, then use SendLCDFrame from
http://wakaba.c3.cx/w/dingoo_coding to update the screen.
Unsure if the DOUBLEBUF approach will work for TV-out.
Ideas from joyrider at
http://boards.dingoonity.org/dingoo-development/native-now-has-sdl/msg20690/#msg
20690