Show Google+ button when no reddit results

People have proven unable to locate the extension options page or has
expressed dissatisfaction with the current way of handling no results,
a switch to Google+ button will now be added to the “no results” page.

xlexi/alientube#72
xlexi/alientube#71
xlexi/alientube#70
xlexi/alientube#69
xlexi/alientube#66
xlexi/alientube#65
xlexi/alientube#64
xlexi/alientube#62