Add initial support for charge mode. also support recovery/root in the device tree to easily copy props into recovery images.

Change-Id: Icf773a49f2802e3b287b970a390339f1ba0c7aad
fix rc file for charge mode

Change-Id: I62d881228bf309409a994d45f878d9ff331f93c1
kernel.mk: make use of ccache when requested

Change-Id: I9b6e28711bd5f590a76ac2b62a50b1d2de014e3e

Conflicts:
	core/tasks/kernel.mk