"Enhancements" to link method

Minor improvement to link method, can pass optional attributes

    link(page.html", "Page", :title => 'click me', :class => 'active')
    
  becomes...

    <a title="click me" class="active" href="page.html />
    
Also, fixed an issue with the link method, and absolute urls. Previously link stripped the first slash after the protocol definition

    http://example.com → http:/example.com