Revert "Revert Koush's superuser we include SuperSu"

This reverts commit 35ecd004b9e531da90ef07d3d1ad82c2a854eb35.
Revert "Implementation of Koush superuser (2/3)"

This reverts commit 688100ec71cca27a1d7b7cb64bc7300db907a138.

Change-Id: Ie7b2200bd46587cbcb1924990ec01bbe549267d8