add error handler pages for 400, 404, 500

incorporealcms/templates/400.html

@@ -0,0 +1,14 @@
+{% extends "base.html" %}
+
+{% block header %}
+<div class="header">
+    <a href="/">{{ config.TITLE_SUFFIX }}</a>
+</div>
+{% endblock %}
+
+{% block body %}
+<div class="content">
+    <h1>BAD REQUEST</h1>
+    <p>You're doing something you're not supposed to. Stop it?</p>
+</div>
+{% endblock %}

incorporealcms/templates/404.html

@@ -0,0 +1,19 @@
+{% extends "base.html" %}
+
+{% block header %}
+<div class="header">
+    <a href="/">{{ config.TITLE_SUFFIX }}</a>
+</div>
+{% endblock %}
+
+{% block body %}
+<div class="content">
+    <h1>NOT FOUND</h1>
+    <p>Sorry, <b><tt>{{ request.path }}</tt></b> does not seem to exist, at least not anymore.</p>
+    <p>It's possible you followed a dead link on this site, in which case I would appreciate it if you could email me via:
+    bss @ &lt;this domain&gt; and I can take a look. I make an effort to symlink old content to its new location,
+    so old links and URLs should, generally speaking, work.</p>
+    <p>Otherwise, I suggest you go <a href="/">to the index</a> and navigate your way (hopefully) to what
+    you're looking for.</p>
+</div>
+{% endblock %}

incorporealcms/templates/500.html

@@ -0,0 +1,14 @@
+{% extends "base.html" %}
+
+{% block header %}
+<div class="header">
+    <a href="/">{{ config.TITLE_SUFFIX }}</a>
+</div>
+{% endblock %}
+
+{% block body %}
+<div class="content">
+    <h1>INTERNAL SERVER ERROR</h1>
+    <p>Something bad happened! Please email me at bss @ &lt;this domain&gt; and tell me what happened.</p>
+</div>
+{% endblock %}

incorporealcms/templates/base.html

@@ -12,6 +12,7 @@
 <link rel="icon" href="{{ url_for('static', filename='img/favicon.png') }}">
 
 <div class="site-wrap">
+    {% block header %}
     <div class="header">
         <div class="nav">
             {% for nav in navs %}
@@ -24,11 +25,14 @@
             <a href="?style=light">[light]</a>
         </div>
     </div>
+    {% endblock %}
+    {% block body %}
     <div class="content">
         {{ content }}
     </div>
     <footer>
         <i>Last modified: {{ mtime }}</i>
     </footer>
+    {% endblock %}
 </div>
 </html>