Improve initial download and build experience

[wwahammy]

Right now, the current clone and build experience isn't very user intuitive. Ideally, the user should be able to run a single make command and do the following:

• [ ] install the set of packages necessary for a proper build
• [ ] install the flashing utility (maybe)
• [ ] install proper toolchain locally
• [ ] build an image (or all of the images)

The OpenWrt folks have done a pretty good job of handling this through their use of buildroot. We should consider reusing buildroot or similar utility