Implement Threaded Events to speed it up !!!

[asmodehn]

We need to implement that in order to speed up events handling.
Carefull : have to link that with the EVENTTHREAD flag in SDL.
IF no thread, old way, if thread : do it the fast way
http://www.gameprogrammer.com/fastevents/fastevents1.html

[asmodehn]

This is likely to be dropped because of SDL moving to 1.3
I t snot that much interesting to do where we are right now anyway. so maybe later if someone 's got time...