Remove unnecessary 'on' from en/libraries page
Merge pull request #772 from j1wilmot/patch-1

Remove unnecessary 'on' from libraries page (en)
Update Ruby-forum.org --> Ruby-forum.com and more (pt)
Fix small typo and Archives references (pt)
Fix Documentation Archives link (pt)
Add comp.lang.ruby Newsgroup line (pt)
Fix links to Ruby-PT group (pt)
Add note refering to lists.ruby-lang.org (pt)
Add emphasis on 'controller address' (pt)
Add alert about not using HTML e-mail (pt)