Notify plugins on certain events (e.g. body added).

This also adds a periodic tick function to plugins, giving them periodically control over the simulation thread, even when the simulation is paused.

examples/SharedMemory/PhysicsCommandProcessorInterface.h

@@ -44,6 +44,8 @@ public:
 	virtual void enableRealTimeSimulation(bool enableRealTimeSim)=0;
 	virtual bool isRealTimeSimulationEnabled() const=0;
 
+	virtual void tickPlugins() = 0;
+
 	virtual void enableCommandLogging(bool enable, const char* fileName)=0;
 	virtual void replayFromLogFile(const char* fileName)=0;
 	virtual void replayLogCommand(char* bufferServerToClient, int bufferSizeInBytes )=0;