Make UI display double buffered

Signed-off-by: James Tasker <james_tasker1@hotmail.com>
Add backgroundmode variable in skin

Signed-off-by: James Tasker <james_tasker1@hotmail.com>
Add background properties to skin

Signed-off-by: James Tasker <james_tasker1@hotmail.com>
Load bitmaps from streams so that files dont become locked

Signed-off-by: James Tasker <james_tasker1@hotmail.com>