Fix typescript 1.6 compile errors.

- Remove unknown properties in object literals.
- Don't use module-level `delete` statements.

apps/tests/ui/scroll-view/scroll-view-tests.ts

@@ -49,9 +49,9 @@ export function setUpModule() {
 
 export function tearDownModule() {
     helper.goBack();
-    delete tmp;
-    delete newPage;
-    delete scrollView;
+    tmp = null;
+    newPage = null;
+    scrollView = null;
 }
 
 export function setUp() {

apps/tests/ui/style/style-properties-tests.ts

@@ -25,8 +25,8 @@ export function setUpModule() {
 
 export function tearDownModule() {
     helper.goBack();
-    delete testBtn;
-    delete testPage;
+    testBtn = null;
+    testPage = null;
 }
 
 export function tearDown() {
@@ -362,4 +362,4 @@ function test_native_font(style: string, weight: string) {
         TKUnit.assertEqual((<UIButton>testView.ios).titleLabel.font.fontName.toLowerCase(), (fontName + "-" + fontNameSuffix).toLowerCase(), "native font " + weight + " " + style);
     }
     //TODO: If needed add tests for other platforms
-}
+}