Add arrows for prev/next on release page

     $if not (prev or next):
         no other releases
     $if prev:
-        <a rel=prev href=/projects/$project/releases/$prev>$prev</a>
+        &larr; <a rel=prev href=/projects/$project/releases/$prev>$prev</a>
     $if prev and next:
         &mdash;
     $if next:
-        <a rel=next href=/projects/$project/releases/$next>$next</a>
+        <a rel=next href=/projects/$project/releases/$next>$next</a> &rarr;
     </p>
 $var aside = aside()