AMO URL change

I changed the URL of the addon's listing on AMO from https://addons.mozilla.org/en-us/firefox/addon/social-friend-finder/ to https://addons.mozilla.org/en-us/firefox/addon/sff/ in order to reflect the shortened version of the addon's name (SFF). Also I added the shortened name to page's title.

So from now on to visit SFF's AMO listing follow use the new URL: https://addons.mozilla.org/en-us/firefox/addon/sff/