[yocto] What hosts do we support?

[deVries, Alex]

I think we're at the point where we should think of what makes a host supported, and what expectations we have of that host. The situation is undocumented and a bit frustrating today.  

It should be really easy to get going with YML/poky. We should consider optimizing the following workflow:
1. Install a minimal distribution
2. Download YML/poky, run it
3. Follow only the instructions provided
4. Complete a build

It may be required that the user has root access temporarily to update packages.  Only packages provided by the distribution vendor should need to be installed. The user should only have to make changes once.  The need for these changes should be minimized.

Yocto can then advertise a finite list of supported distributions, with the goal of widening the list over time.

Feedback?  Are these reasonable guidelines?


- A