Markdown editor: Fix the redo button + remove the button hover flicker

src/Umbraco.Web.UI.Client/lib/markdown/markdown.css

@@ -26,6 +26,11 @@
 	width: 100%;
 }
 
+/* unset the negative margin applied in button-groups.less to avoid flickering when hovering the button bar */
+.wmd-panel .btn-toolbar .btn-group>.btn+.btn {
+    margin-left: 0;
+}
+
 /*
 .icon-link,
 .icon-blockquote,

src/Umbraco.Web.UI.Client/lib/markdown/markdown.editor.js

@@ -1390,7 +1390,7 @@
                 "Redo - Ctrl+Y" :
                 "Redo - Ctrl+Shift+Z"; // mac and other non-Windows platforms
 
-            buttons.redo = makeButton("wmd-redo-button", redoTitle, "icon-share-alt", null, group4);
+            buttons.redo = makeButton("wmd-redo-button", redoTitle, "icon-redo", null, group4);
             buttons.redo.execute = function (manager) { if (manager) manager.redo(); };
 
             if (helpOptions) {
@@ -2107,4 +2107,4 @@
     }
 
 
-})();
+})();