Use fixed size integer type

This type is meant to be 4 bytes large as seen in _XcursorReadUInt which
always reads 4 bytes. An unsigned int is often 4 bytes large but this
isnt' guaranteed so it is cleaner to use the exact type we want.

include/xcursor/xcursor.h

@@ -26,8 +26,10 @@
 #ifndef XCURSOR_H
 #define XCURSOR_H
 
+#include <stdint.h>
+
 typedef int XcursorBool;
-typedef unsigned int	XcursorUInt;
+typedef uint32_t XcursorUInt;
 
 typedef XcursorUInt	XcursorDim;
 typedef XcursorUInt	XcursorPixel;