autogroup sched: per-uid task group for android
and enable autogroup scheduler

Thanks to Andrea Righi
http://arighi.blogspot.com/2011/01/android-automated-per-uid-task-group.html
backport lowmemorykiller from AOSP android-3.4 kernel
backport android logger updates from AOSP android-3.4 kernel
fix compiler string for prerelease compilers
so that kernel version in software information looks okay
and add signature
add compiler flags