make post numbers insert backlink on click

contrib/static/nntpchan.js

@@ -0,0 +1,11 @@
+//
+// nntpchan.js -- frontend ui niceness
+//
+
+
+// insert a backlink for a post given its short hash
+function nntpchan_backlink(shorthash) {
+  var elem = document.getElementById("postform_message");
+  elem.value += ">>" + shorthash + "\n";
+
+}