Add a "add button" option in the CommonParameterInterface and implement it for Gwen.

Add some buttons for shared memory requests in the PhysicsClient

examples/ExampleBrowser/GwenGUISupport/GwenParameterInterface.h

@@ -12,6 +12,8 @@ struct GwenParameterInterface : public CommonParameterInterface
 	GwenParameterInterface(struct GwenInternalData* gwenInternalData);
 	virtual ~GwenParameterInterface();
 	virtual void registerSliderFloatParameter(SliderParams& params);
+	virtual void registerButtonParameter(ButtonParams& params);
+
     virtual void setSliderValue(int sliderIndex, double sliderValue);
 	virtual void syncParameters();
 	virtual void removeAllParameters();