added a simple builder API to the std.dom API

testlib/test/dom/DomBuilderTest.kt

@@ -0,0 +1,27 @@
+package test.dom
+
+import std.*
+import std.dom.*
+import stdhack.test.*
+import org.w3c.dom.*
+
+class DomBuilderTest() : TestSupport() {
+
+    fun testBuildDocumnet() {
+        var doc = createDocument()
+
+        doc.addElement("foo") {
+            id = "id1"
+            style = "bold"
+            cssClass = "bar"
+            addElement("child") {
+                cssClass = "another"
+                addElement("grandChild") {
+                    cssClass = "tiny"
+                    addText("Hello World!")
+                }
+            }
+        }
+        println("builder document: ${doc.toXmlString()}")
+    }
+}