Remove AOSP su
Add make_ext4fs utility

Add make_ext4fs into $OUT/Utilities needed for some devices like Galaxy S I9000
Yet another MMC discard pain in the ass

 * Secure discard on some devices are painfully slow.
Make memtrack an optional module.

This isn't really _needed_ (someone correct me if I'm wrong), and
right now it's preventing some of us from building for flounder
because of the segfaults in ld.

Change-Id: I5bdf81e1daca757e332447af61523c9e2b941a70