[#18678] Swizzle properties for Mathutils.Vector

patch from Alex Fraser (z0r)

eg.
  - vec.xyz = vec.zyx
  - vec.xy = vec.zw
  - vec.xxy = vec.wzz
  - vec.yzyz = vec.yxyx

See http://en.wikipedia.org/wiki/Swizzling_(computer_graphics)

made some minor modifications to this patch.

tested access times and adding 336 attributes to vectors doesn't make a noticeable differences to speed of existing axis attributes (x,y,z,w) - thanks to python dict lookups.

source/blender/python/api2_2x/vector.h

@@ -43,6 +43,10 @@ typedef struct {
 	short wrapped;			/* is wrapped data? */
 } VectorObject;
 
+void	Vector_Free(void);
+int		Vector_Init(void);
+
+
 /*prototypes*/
 PyObject *Vector_Zero( VectorObject * self );
 PyObject *Vector_Normalize( VectorObject * self );