Update port to version 8.0 (R8B-0).
Remove my code to handle the documentation merge for patched releases, it
was rather obscure and error-prone. I'll rewrite it in a simpler way next
time I'll need to perform the merge.
Also include a fix for erlang-mode under emacs21 (by Hal Snyder
<hal@vailsys.com> on the erlang mailing list).