Don't draw the watermark

I don't think it much use (besides seeing what versions testers are using):

1. most people disable it anyway (we even advise them to on the wiki) so they need to look up the version using some other means
2. it reports the client version which is 90% of the time not what people want when reporting bugs

I kept the function even though it's empty in case somebody wants to draw something else later so they don't have to figure out where to put it. Maybe we should remove that as well?