Policy proposal for partner repository

[Allison Randal]

Nick, Steve George, and I have been working on merging the policies for 
Extras, Partner, and Commercial. The merged text is on the original wiki 
page:

https://wiki.ubuntu.com/PartnerRepositoryPolicy

(We've renamed it to "Extension Repository Policy" as a more general 
name to cover the three.)

Partner and Extras assume a certain level of background with Ubuntu, so 
we aimed for a quick-reference/checklist policy. The Commercial 
repository is planning to use this policy as a base, expanding on it 
with more explanation and illustration in an easier format for 
commercial developers.

Review welcome (here or in today's Tech Board meeting).

Allison