While updating Huenison I noticed that a bug in some versions of gcc could cause corrupted graphics and even memory faults. Although KOG didn't seem affected by that problem, I thought I'd better make sure - and, while at it, I also made a few more little changes.

* Reworked assignments of the kind *p++ = ... *p ... (as they are miscompiled by some versions of gcc).
* Removed assignment of function "back" to joypad first button (as that was confusing).
* Added Windows portable version.
* Worked on Windows installer: removed unused data directory; added logo to graphics.