nsIControllerContext in Firefox 3.6a1pre

  Init the controller, optionally passing a controller
  command table.

 @param aCommandTable  a command table, used internally
                       by this controller. May be null, in
                       which case the controller will create
                       a new, empty table.

 
  Set a context on this controller, which is passed
  to commands to give them some context when they execute.

 @param aCommandContext  the context passed to commands.
                        Note that this is *not* addreffed by the
                        controller, and so needs to outlive it,
                        or be nulled out.