Replicate method and event listener changes

@eric79, this is the two existing PRs,

  - Replicate method changes  (https://github.com/virtual-world-framework/vwf/pull/276)
  - Replicate event listener changes (https://github.com/virtual-world-framework/vwf/pull/292)

plus the `preserve-script-closures` compatibility option, and method and event listener replication tests.

These are working towards having the internal registry be authoritative about valid nodes and members. The next step will be to handle errors here (and not in model/object, where it's too late) when invalid node IDs or member names are passed to kernel actions.