dtext: fix flicker in [expand] elements.

app/javascript/src/javascripts/dtext.js

@@ -11,7 +11,6 @@ Dtext.initialize_links = function() {
 
 Dtext.initialize_expandables = function($parent) {
   $parent = $parent || $(document);
-  $parent.find(".expandable-content").hide();
   $parent.find(".expandable-button").click(function(e) {
     var button = $(this);
     button.parent().next().fadeToggle("fast");

app/javascript/src/styles/common/dtext.scss

@@ -79,6 +79,7 @@ div.prose {
   }
 
   div.expandable-content {
+    display: none;
     padding: 0.4em;
     border-top: 1px solid #666;