Port Superuser from CyanogenMod
prepare for switch to new superuser

Change-Id: I69c992928e6552a76ba880a399d08e4f59d348e3

Conflicts:
	config/common.mk

add SUPERUSER_PACKAGE_PREFIX in prep for switch to new superuser

Change-Id: I0b880a6d0f9cf36c0a8419ec00fc978245adbb6f

Conflicts:
	config/common.mk

Include Superuser and init.local.rc from CyanogenMod