Changed order of buttons to match order of cheat sheet

cms/templates/widgets/problem-edit.html

@@ -4,6 +4,8 @@
         %if markdown != '' or data == '<problem>\n</problem>\n':
         <div class="editor-bar">
             <ul class="format-buttons">
+                <li><a href="#" class="header-button" data-tooltip="Header"><span
+                        class="problem-editor-icon dropdown"></span></a></li>
                 <li><a href="#" class="multiple-choice-button" data-tooltip="Multiple Choice"><span
                         class="problem-editor-icon multiple-choice"></span></a></li>
                 <li><a href="#" class="checks-button" data-tooltip="Check Multiple"><span
@@ -14,8 +16,6 @@
                         class="problem-editor-icon number"></span></a></li>
                 <li><a href="#" class="dropdown-button" data-tooltip="Option Response"><span
                         class="problem-editor-icon dropdown"></span></a></li>
-                <li><a href="#" class="header-button" data-tooltip="Header"><span
-                        class="problem-editor-icon dropdown"></span></a></li>
                 <li><a href="#" class="explanation-button" data-tooltip="Explanation (aka Solution)"><span
                         class="problem-editor-icon dropdown"></span></a></li>
             </ul>