fix for GUI in ie11

gui/src/controls/control.ts

@@ -868,7 +868,7 @@ module BABYLON.GUI {
                 block.style.verticalAlign = "baseline";
                 fontAscent = block.getBoundingClientRect().top - text.getBoundingClientRect().top;
             } finally {
-                div.remove();
+                document.body.removeChild(div);
             }
             var result = { ascent: fontAscent, height: fontHeight, descent: fontHeight - fontAscent };
             Control._FontHeightSizes[font] = result;