Add backuptool support to the releasetools system

Pulled from CyanogenMod 10.1

Change-Id: Iffd9a45865011ad9108508d31f79e53d609dd6f4
Allow prebuild APK's in Vendor
OTA: Add more info while flashing

Conflicts:
	tools/releasetools/ota_from_target_files
ota release tools: comment out stock recovery

Conflicts:
	tools/releasetools/ota_from_target_files