Fixing custom widgets support:

> Moving the definitions to xml so that it is easier to override in derivative projects
> Fixing verious bind and save logic for custom widgets
> Adding feature flag to easily disable custom widgets

Change-Id: I0e278bc7dd415713029364060ef10842da990be9
diff --git a/src/com/android/launcher3/LauncherAppWidgetHost.java b/src/com/android/launcher3/LauncherAppWidgetHost.java
index 5573c5c..819f23f 100644
--- a/src/com/android/launcher3/LauncherAppWidgetHost.java
+++ b/src/com/android/launcher3/LauncherAppWidgetHost.java
@@ -116,7 +116,7 @@
 
     public AppWidgetHostView createView(Context context, int appWidgetId,
             LauncherAppWidgetProviderInfo appWidget) {
-        if (appWidget.isCustomWidget) {
+        if (appWidget.isCustomWidget()) {
             LauncherAppWidgetHostView lahv = new LauncherAppWidgetHostView(context);
             LayoutInflater inflater = (LayoutInflater)
                     context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);