Implement failing tests for Point#equals().

As needed to fix #235

test/tests/Point.js

@@ -87,4 +87,18 @@ test('getDirectedAngle(point)', function() {
 
 	var angle = new Point(10, -10).getDirectedAngle(new Point(1, 0));
 	equals(angle, 45);
-});
+});
+
+test('equals()', function() {
+	equals(function() {
+		return new Point(10, 10).equals([10, 10]);
+	}, true);
+
+	equals(function() {
+		return new Point(0, 0).equals({});
+	}, false);
+
+	equals(function() {
+		return new Point(0, 0).equals(null);
+	}, false);
+});