Use new offmode_charging and images

HTC incorporated charger functionality into offmode_charging and added
1% increment images. This makes offmode charging look much nicer. Also,
bring back detect_key and power_test so that the power button works to
turn-on the device from offmode.

Take this opportunity to do a little directory cleanup, too.

Blobs from m7wlv 5.28.605.2.