Merge the Sky Engine changes from the SkyDart branch

sky/tests/lowlevel/camel-case.sky

 <CamelCase>
-<import src="../resources/chai.sky" />
-<import src="../resources/mocha.sky" />
 <script>
-describe('Element tag names', function() {
-  it('should have various casing', function() {
-    assert.equal(document.documentElement.tagName, 'CamelCase');
+import "../resources/third_party/unittest/unittest.dart";
+import "../resources/unit.dart";
+
+import "dart:sky";
+
+void main () {
+  initUnit();
+
+  test('should have various casing', () {
+    expect(document.documentElement.tagName, equals('CamelCase'));
 
     var element = document.createElement('CamelCase');
-    assert.equal(element.tagName, 'CamelCase');
+    expect(element.tagName, equals('CamelCase'));
   });
-});
+}
 </script>
 </CamelCase>