Plug the Android SDK window as the AVD manager.

- the "manager" button on the AVD selector (when not in manager
  will open the Android SDK window

- the AVD manager in the eclipse toolsbar open the Android SDK
  window as well.

Still left to do:
- remove the now obsolete AVD wizard
- figure out what to do with the other pages.

tools/sdkmanager/app/src/com/android/sdkmanager/Main.java

@@ -243,6 +243,7 @@ class Main {
             System.out.printf("No command line parameters provided, launching UI.\n" +
                     "See 'android --help' for operations from the command line.\n");
             UpdaterWindow window = new UpdaterWindow(
+                    null /* parentShell */,
                     mSdkLog,
                     mOsSdkFolder,
                     false /*userCanChangeSdkRoot*/);