/*
  * (non-Javadoc)
  * @see org.eclipse.ui.plugin.AbstractUIPlugin#stop(org.osgi.framework.BundleContext)
  */
 public void stop(BundleContext context) throws Exception {
   RuleManager.closeConnection();
   plugin = null;
   super.stop(context);
 }
 /*
  * (non-Javadoc)
  * @see org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.BundleContext)
  */
 public void start(BundleContext context) throws Exception {
   super.start(context);
   plugin = this;
   ensureRuleDatabase();
   RuleManager.openConnection();
 }