Removing Optical Boot Requirement from F20 Alpha Release Requirements

[Kamil Paral]

> The rewrite sounds good to me.  Just one possible improvement.  I work
> almost exclusively with VM for testing so iso size doesn't matter.
> Should it be an alpha requirement that the isos we're talking about
> boot and install in the VM environment which has no care for size?

I think that should be implicitly covered by "All release-blocking images must boot in their supported configurations. ". But it's true we could explicitly mention VMs as a supported "architecture" (or something).