### Function: lookup-image-map

Lookup in image map MAP coordinates X and Y.

An image map is an alist where each element has the format (AREA ID PLIST).

An AREA is specified as either a rectangle, a circle, or a polygon:

A rectangle is a cons (rect . ((x0 . y0) . (x1 . y1))) specifying the

pixel coordinates of the upper left and bottom right corners.

A circle is a cons (circle . ((x0 . y0) . r)) specifying the center

and the radius of the circle; r may be a float or integer.

A polygon is a cons (poly . [x0 y0 x1 y1 ...]) where each pair in the

vector describes one corner in the polygon.

Returns the alist element for the first matching AREA in MAP.
(fn MAP X Y)