Fix h* display size in HtmlFormat, and fix images being wider than the page.

static/HtmlFormat.css

@@ -5,7 +5,6 @@ html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockq
     border: 0;
     outline: 0;
     font-size: 100%;
-    font: inherit;
     vertical-align: baseline;
 
 }
@@ -111,3 +110,8 @@ button.backbutton, button.rss-feed {
 
 }
 
+img {
+
+  max-width: 100%;
+
+}