Make a copy of libmincrypt in TWRP source so we do not have to
ifdef verifier.cpp for various versions of mincrypt.
Remove reboot tool from toolbox (it was removed from 4.4 and did
not compile properly on some devices in older trees)
Move all the functions in ui.c to be members of a ScreenRecoveryUI
class, which is a subclass of an abstract RecoveryUI class. Recovery
then creates a global singleton instance of this class and then invoke
the methods to drive the UI. We use this to allow substitution of a
different RecoveryUI implementation for devices with radically
different form factors (eg, that don't have a screen).
Change-Id: I76bdd34eca506149f4cc07685df6a4890473f3d9