added ag::setGravity() so the script programmer can change the world gravity

git-svn-id: svn://anubis/anaglym/trunk@200 99a6e188-d820-4881-8870-2d33a10e2619

doc/index.html

@@ -393,6 +393,13 @@ The default center point is (0, 0, 0).
 The default up vector is (0, 0, 1).
 </p>
 
+<a name="ag_setGravity" />
+<h3>setGravity</h3>
+<p><tt>ag.setGravity(gx, gy, gz)</tt></p>
+<p>
+This function sets the gravity vector to (gx, gy, gz).
+</p>
+
 <a name="ag_startFrame" />
 <h3>startFrame</h3>
 <p><tt>ag.startFrame()</tt></p>