dont render gui elements like progressbar when screen timed out (display off)

twrp redraws gui elements even if the display is turned off, which is
unlogical and eats battery
set & use interactive gov

better cpu state handling - turn off cores when not needed. speeds up
backup time by about 10%
changed dimming delay

normally it dims the screen 3 seconds before it actually gets turned
off. it dont get how this is useful.
it dims now after screentimeout/3 seconds