r8635: make object inheritance with the builtin objects easy by allowing

r8635: make object inheritance with the builtin objects easy by allowing
callers to optionally supply an existing object to add the properties
to. So you can do:

 var rpc = samr_init();
 lsa_init(rpc);

and you end up with 'rpc' having both the samr and lsa functions and
constants available.
(This used to be commit 6a1ed328e27769bd52899fc2437a43fc17104eff)