Add image to radio widget

build/perseus-1.css

@@ -275,10 +275,11 @@
   float: none;
   margin: 3px;
 }
-.perseus-widget-radio div,
-.perseus-widget-radio div > p {
-  /* TODO(alpert): Find a better way of doing inline renderers */
-  display: inline;
+.content-editor * {
+  max-height: 400px;
+}
+.content-editor .perseus-textarea-underlay {
+  overflow: hidden;
 }
 .perseus-widget-radio li {
   padding: 7px 0;