Fix some layout problems, and caching issues.

sidebar.inc.php

@@ -1,7 +1,3 @@
-<?
-if (!isset($is_admin))
-  $is_admin=FALSE
-?>
 <aside id="sidebar">
 
 <div class="logo">
@@ -22,7 +18,7 @@ if (preg_match("#^(/$|/index)#", $_SERVER['REQUEST_URI'])) {
 <li><a href="/about">About <span class="xxx">x&middot;x&middot;x</span></a></li>
 <li><a href="/article?start=5">Archive</a></li>
 <li><a href="/publish">Add</a>/<a href="/publish/edit" class="sidelink">Edit</a></li>
-<? if ($is_admin) {
+<? if (isset($is_admin) && $is_admin) {
   echo '<li><a href="/publish/addeditor">Add editor</a></li>';
   echo '<li><a href="/publish/logout">Logout</a></li>';
 }