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.

I don't think so. `haveOwn` is used to pull local versions of `existing` and `changes` up into the deriving nodes. But that doesn't affect the `hasOwn` function. `haveOwn( "hasOwn" )` would obscure it, but we don't do that.