Remove protocol from external script includes

Removed protocol from script src as per http://www.paulirish.com/2010/the-protocol-relative-url/ so that scripts actually work when site is loaded over an https connection. Also, jquery 2+ won't work on IE<9 which might confuse some newbies wondering why the javascript wasn't coming up. Once they've got the site working, they can easily switch to the 2.x jQuery branch.