Add onMessage(id, data) to plugin API.

A solution was needed to notify the audio player to pause when a phone call comes in. The option was to add a specific onPhone() method or generalize it. Since there are other "events" that are useful to plugins, a generalized solution was used. It is also extensible without changing the plugin API again.

Any plugin can call DroidGap.onMessage() to send a message/event to all other plugins. NetworkManager was updated to send changes in connection status to plugins, so they can intelligently handle lost connections.

framework/src/com/phonegap/DroidGap.java

@@ -814,6 +814,18 @@ public class DroidGap extends PhonegapActivity {
         }
     }
 
+    /**
+     * Send a message to all plugins. 
+     * 
+     * @param id            The message id
+     * @param data          The message data
+     */
+    public void onMessage(String id, Object data) {
+        
+        // Forward to plugins
+        this.pluginManager.onMessage(id, data);
+    }
+
     /**
      * Add a class that implements a service.
      *