add template support for minor/major labels (#2493)

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

lib/timeline/component/TimeAxis.js

@@ -332,8 +332,7 @@ TimeAxis.prototype._repaintMinorText = function (x, text, orientation, className
     this.dom.foreground.appendChild(label);
   }
   this.dom.minorTexts.push(label);
-
-  label.childNodes[0].nodeValue = text;
+  label.innerHTML = text;
 
   label.style.top = (orientation == 'top') ? (this.props.majorLabelHeight + 'px') : '0';
 
@@ -364,7 +363,8 @@ TimeAxis.prototype._repaintMajorText = function (x, text, orientation, className
 
   if (!label) {
     // create label
-    var content = document.createTextNode(text);
+    var content = document.createElement('div');
+    content.innerHTML = text;
     label = document.createElement('div');
     label.appendChild(content);
     this.dom.foreground.appendChild(label);