CVS docs referencing externals

When fixing the fact that the new cvs docs (how to pull with rsync) in HEAD
refer to the wrong hostname for rsync, I (or rather, Dave, during our
discussions) noticed two external references:

http://developer.postgresql.org/pgdocs/postgres/cvs.html refers with a link
to the developer wiki, and
http://developer.postgresql.org/pgdocs/postgres/rsync.html refers to the
buildfarm instructions.

First of all, neither of these URLs are guaranteed to be stable. Second,
should we really be referring to external URLs for such information?
Wouldn't it be better to include a version of the text directly in our
docs, so people can actually read it if these URLs/contents change?

//Magnus