Release criterion proposal: betanag removal

[Kamil Paral]

> A straightforward release criterion proposal: we should have a
> criterion
> just to specify that the anaconda betanag screen (and any others we
> put
> in) should be removed for final. Right now this is one of those
> things
> that's "just obvious" but that we ought to write down somewhere. How
> about, in the Final criteria, simply:
> 
> * No notices or alerts about pre-release status should be present
> 
> Comments, suggestions, etc? Thanks!

I thought we had it, but we don't! ACKed