======Event_ToolbarAction======
This event is sent to the plugin when clicking on a toolbar button of the plugin.

The event cannot be switched off.

===Values===
  * **//(integer) windowhandle//** - Windowhandle of the current GRT main window
  * **//(string) id//** - ID of the clicked button
  * **//(string) label//** - text of the clicked button

===JSON source (example)===
<code>
{
  "Event_ToolbarAction":{
    "windowhandle":531876,
    "id":"com.grt.plugin.tester.toolbar_button1",
    "label":"Example Plugin"
  }
}
</code>