Added EVENT_PAUSE, EVENT_RESUME events to MOAISim

Added EVENT_PAUSE, EVENT_RESUME event to MOAISim according to issue https://github.com/moai/moai-dev/issues/599
These events are extremely important for any online game due to valid connection opening and closing.

Now MOAI pause (resume) event can be caught using snippets:
```MOAISim.setListener(MOAISim.EVENT_PAUSE, function() print('pause') end)```