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

Change-Id: Icf773a49f2802e3b287b970a390339f1ba0c7aad

Conflicts:
	core/Makefile
	tools/device/BoardConfig.mk.template
	tools/device/device.mk.template
	tools/device/mkvendor.sh
build: recovery: Support adding device-specific items

(cdesai): Also add the relevant parts from koush's
commit 7fd5a89df5ec3961c9aedfd2afad50d6d2561056
"Add initial support for charge mode. also support recovery/root in the device tree to easily copy props into recovery images."

Change-Id: I25205e68282680932917016646dabd1abadbfce6