Use Drawer in Settings app

- get rid of PreferenceActivity as much as we can and use fragments instead
- add Drawer widget
- add Dashboard high level entry into the Drawer (but this is work in progress and would be done in another CL)
- add bypass of fragment's Header  validation when launched from the Drawer but *force* validation if external
call thru an Intent

Be aware that WifiPickerActivity should remain for now a PreferenceActivity. It is used by SetupWizard and should
not trigger running the SettingsActivity's header building code. SetupWizard is a Home during the provisionnig process
and then deactivate itself as a Home but would make the Home header to appear in the Drawer (because momentarily we
would have two Home).

Also, verified that:

- the WiFi settings still work when called from SetupWizard
- when you have multiple Launchers, the Home header will appear in the list of Headers in the Drawer

Change-Id: I407a5e0fdd843ad7615d3d511c416a44e3d97c90

src/com/android/settings/inputmethod/UserDictionaryAddWordFragment.java

@@ -18,7 +18,6 @@ package com.android.settings.inputmethod;
 
 import android.app.Fragment;
 import android.os.Bundle;
-import android.preference.PreferenceActivity;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -29,6 +28,7 @@ import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 
 import com.android.settings.R;
+import com.android.settings.SettingsActivity;
 import com.android.settings.inputmethod.UserDictionaryAddWordContents.LocaleRenderer;
 
 import java.util.ArrayList;
@@ -137,8 +137,8 @@ public class UserDictionaryAddWordFragment extends Fragment
             final long id) {
         final LocaleRenderer locale = (LocaleRenderer)parent.getItemAtPosition(pos);
         if (locale.isMoreLanguages()) {
-            PreferenceActivity preferenceActivity = (PreferenceActivity)getActivity();
-            preferenceActivity.startPreferenceFragment(new UserDictionaryLocalePicker(this), true);
+            SettingsActivity sa = (SettingsActivity)getActivity();
+            sa.startPreferenceFragment(new UserDictionaryLocalePicker(this), true);
         } else {
             mContents.updateLocale(locale.getLocaleString());
         }