13.12: add Robin's feedback

Robin requested that I add the line:

"Please note that no new big.LITTLE MP specific functionality or fixes
have been added in this release."

Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
13.12: add hwpack and rootfs build date & number

Add the exact build date and number to the hwpack and rootfs filenames.

Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>