bb.org: add u-boot v2013.10 source patches

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
bb.org: add uEnv.txt cape variable (not used yet)

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
bb.org: change background image for flasher images

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>