upgrade source to 2.0.8

Edward Rudd

2018-08-19 561f0d614098a95527367cc3f911e476f35643d6

 source/Xcode-iOS/Demos/src/touch.c

@@ -5,7 +5,7 @@
 */

#include "SDL.h"
#include "math.h"
#include <math.h>
#include "common.h"

#define BRUSH_SIZE 32           /* width and height of the brush */