fix numeric_score to use make_link for user profile links

After following the 'See All Votes' link on a post's page, it provides a list of users that voted.  This is a list of links which point to user profiles; however, they are not created using make_link, and instead were referencing the http root ("/user/username").  

This causes problems when Shimmie is located in a subdirectory off of the site root, such as in the example http://example.com/shimmie2/user/myuser.  

This commit updates the extension to use make_link, which is preferred over direct use of relative links.