Add IDBKeyRange to dart:html, port two indexeddb tests

lib/dom/templates/html/interface/interface_IDBKeyRange.darttemplate

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// WARNING: Do not edit - generated code.
+
+$!COMMENT
+interface $ID$EXTENDS default _IDBKeyRangeFactoryProvider {
+
+  /**
+   * @domName IDBKeyRange.only
+   */
+  IDBKeyRange.only(/*IDBKey*/ value);
+
+  /**
+   * @domName IDBKeyRange.lowerBound
+   */
+  IDBKeyRange.lowerBound(/*IDBKey*/ bound, [bool open]);
+
+  /**
+   * @domName IDBKeyRange.upperBound
+   */
+  IDBKeyRange.upperBound(/*IDBKey*/ bound, [bool open]);
+
+  /**
+   * @domName IDBKeyRange.bound
+   */
+  IDBKeyRange.bound(/*IDBKey*/ lower, /*IDBKey*/ upper,
+                    [bool lowerOpen, bool upperOpen]);
+
+$!MEMBERS}