Afdarts RTS: version 1.0.4 released

Afdarts 1.0.4 has been released, mainly to fix a frequent overflow that occurred most often when the difficulty level was set to easy.

Changelog:
- initialization error messages are now more detailed
- shadows now enabled by default
- saving videos now temporarily hides FPS
- fixed a frequent overflow in following code
- fixed a few trivial problems
- added detailed Windows Vista directions in Vista setup.htm