Option to have a message on the ban page

Conflicts:
	inc/config.php

inc/config.php

@@ -719,6 +719,10 @@
 	// Automatically remove unnecessary whitespace when compiling HTML files from templates.
 	$config['minify_html'] = true;
 
+	// Optional HTML to append to "You are banned" pages. For example, you could include instructions and/or
+	// a link to an email address or IRC chat room to appeal the ban.
+	$config['ban_page_extra'] = '';
+
 /*
  * ====================
  *  Javascript

templates/banned.html

@@ -76,6 +76,8 @@
 		</span>
 	</p>
 	<p>{% trans %}Your IP address is{% endtrans %} <strong>{{ ban.ip }}</strong>.</p>
+
+	<p>{{ config.ban_page_message }}</p>
 </div>
 {% endfilter %}