start/stop Local Repo from any Activity

This forces the use of the Application's Context, so we can be sure the
webserver will run as long as FDroid is running.  It also checks to make
sure whether the webserver is running before trying to start it.

src/org/fdroid/fdroid/FDroidApp.java

@@ -301,14 +301,17 @@ public class FDroidApp extends Application {
     };
 
     public static void startLocalRepoService(Context context) {
-        context.bindService(new Intent(context, LocalRepoService.class),
+        if (!localRepoServiceIsBound) {
+            Context app = context.getApplicationContext();
+            app.bindService(new Intent(app, LocalRepoService.class),
                     serviceConnection, Context.BIND_AUTO_CREATE);
             localRepoServiceIsBound = true;
         }
+    }
 
     public static void stopLocalRepoService(Context context) {
         if (localRepoServiceIsBound) {
-            context.unbindService(serviceConnection);
+            context.getApplicationContext().unbindService(serviceConnection);
             localRepoServiceIsBound = false;
         }
     }