(svn r2962) - const correctness for all Get* functions and most Draw* functions that don't change their pointer parameters

- change a lot of byte player types to PlayerID
- beautify header files, same "#endif /* filename */" ending

gfx.c

@@ -1991,7 +1991,7 @@ void SortResolutions(int count)
 	qsort(_resolutions, count, sizeof(_resolutions[0]), compare_res);
 }
 
-uint16 GetDrawStringPlayerColor(byte player)
+uint16 GetDrawStringPlayerColor(PlayerID player)
 {
 	// Get the color for DrawString-subroutines which matches the color
 	//  of the player