galaxys2-common: match API to AOSP

See: http://review.cyanogenmod.org/#/c/52047/

Change-Id: I825527ec4a298f98ae6606e6b9ae4b41d5bc8f21
Optimized all png's.

Change-Id: I6b9a374b08a567e92c024df8d16844e7859f8cf7
to: optipng -nc -nb -o7
Stweaks Support

Change-Id: I5ea72126ba84a2e2346fcbeb55ece5117ea1fdc7
Overlay: Use fade out animation instead of crt-off animation

Change-Id: Ib98a70ec828965ab38a333653cf9a1ebaae050f7
wifi.supplicant_scan_interval: 15 -> 30

Change-Id: I93a160e02367ec936980751846338e3fe281fcf6
Revert "galaxys2-common: match API to AOSP"

This reverts commit 7ea48537ecb05144f64ee33d2666ea83f8c6dd4d.