shift span-buttons to real buttons, tweak styles, remove spurious 'hidden' attribute from buttons in course listing.

fixed problem with sometimes not finding feeds in 'common places' - mostly because I'd forgot to finish implementing it. Also addressed #2, I think, and a problem where the URL sometimes had a final / and sometimes not.

addressed part of cogdog's issue #1 regarding the hover support url disappearing and the problem failing to detect facebook.com and complete properly. Also fixed issue where an https addressed site could return a blog feed with http:// as its scheme - due to old blog feed 'ref' notices

Fixed minor markdown error...