Trigger requestDraw when changing TextElement text (#89)

* Fix #85 - orx-panel requestDraw() call

* Clean up imports

orx-panel/src/main/kotlin/org/openrndr/panel/elements/TextElements.kt

@@ -70,12 +70,14 @@ class P : TextElement(ElementType("p"))
 abstract class TextElement(et: ElementType) : Element(et) {
     fun text(text: String) {
         append(TextNode(text))
+        requestRedraw()
     }
     fun replaceText(text : String) {
         if (children.isEmpty()) {
             text(text)
         } else {
             (children.first() as? TextNode)?.text = text
+            requestRedraw()
         }
     }
 }