added lib/demo/checkers.lua; setting window caption to "Anaglym"; added ag::clearWorld() and documentation

git-svn-id: svn://anubis/anaglym/trunk@221 99a6e188-d820-4881-8870-2d33a10e2619

doc/index.html

@@ -56,6 +56,13 @@ with the engine event specified.
 See <a href="#handlers">Lua event handlers</a> for a list of events.
 </p>
 
+<a name="ag_clearWorld" />
+<h3>clearWorld</h3>
+<p><tt>ag.clearWorld()</tt></p>
+<p>
+This function removes all objects from the world.
+</p>
+
 <a name="ag_doPhysics" />
 <h3>doPhysics</h3>
 <p><tt>ag.doPhysics()</tt></p>