removing CVS in Handbook Updating and Upgrading chapter

[Benjamin Kaduk]

On Thu, 24 Jan 2013, Warren Block wrote:

> CVS is going away soon, and we should not be advising people to start using 
> them now.
>
> This diff entirely removes cvsup, csup, and CVS references from the Updating 
> and Upgrading chapter.  SVN URLs are also changed to the preferred form and 
> links to the SVN mirrors are added.
>
> Rendered: http://www.wonkity.com/~wblock/temp/cuttingedge-nocvs.html
>    Diff: http://www.wonkity.com/~wblock/temp/cuttingedge-nocvs.diff

"western US repository" doesn't seem quite right; it is a mirror, not its 
own repository, as I understand it.

"URL previxes for Subversion checkout of the base system" may want to be 
"checkouts"; I didn't fully analyze the sentence structure.

I didn't notice anything else in a quick skim.

-Ben