Chromebook

Added Chromebook support
Updated License
Renamed readme.txt files formatted as markdown to readme.md
Fixed hardcoded uboot source path for Wandboard to a parameter

Worth putting a TODO section at the bottom of this file so people know that this isn't the final configuration.

In particular, it's worth pointing out that the U-Boot image here will be replaced with a version customized for FreeBSD to avoid the need for this.