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/accessibility/ToggleFeaturePreferenceFragment.java

@@ -23,7 +23,6 @@ import android.graphics.Color;
 import android.graphics.drawable.ColorDrawable;
 import android.os.Bundle;
 import android.preference.Preference;
-import android.preference.PreferenceActivity;
 import android.preference.PreferenceScreen;
 import android.view.Gravity;
 import android.view.Menu;
@@ -35,6 +34,7 @@ import android.view.accessibility.AccessibilityManager;
 import android.widget.TextView;
 
 import com.android.settings.R;
+import com.android.settings.SettingsActivity;
 import com.android.settings.SettingsPreferenceFragment;
 
 public abstract class ToggleFeaturePreferenceFragment
@@ -126,8 +126,8 @@ public abstract class ToggleFeaturePreferenceFragment
     }
 
     public void setTitle(String title) {
-        final PreferenceActivity activity = (PreferenceActivity) getActivity();
-        if (!activity.onIsMultiPane() || activity.onIsHidingHeaders()) {
+        final SettingsActivity activity = (SettingsActivity) getActivity();
+        if (!activity.onIsHidingHeaders()) {
             getActivity().setTitle(title);
         }
     }