adding titles and summaries to social media share links

I added parameters into the links instead of using Open Graph tags (og tags) as discussed with Dak. OG tags give us more control over what displays when shared, especially in Twitter. But, this is still a big improvement over what we have now.
`Polyfill` is one word, so no need to cap `Fill`; however, it's probably not necessary to specify it's a polyfill for IE since every browser would be calling this method.  Just `locationOrigin` or `getOrigin` is probably sufficient.