lang/nodejs6: Update to 6.13.0.

- console:
  - added console.count() and console.clear()
- crypto:
  - expose ECDH class
  - added cypto.randomFill() and crypto.randomFillSync()
  - warn on invalid authentication tag length
- deps:
  - upgrade libuv to 1.16.1
- dgram:
  - added socket.setMulticastInterface()
- http:
  - add agent.keepSocketAlive and agent.reuseSocket as to allow
    overridable keep-alive behavior of `Agent`
- lib:
  - return this from net.Socket.end()
- module:
  - add builtinModules api that provides list of all builtin modules
    in Node
- net:
  - return this from getConnections()
- promises:
  - more robust stringification for unhandled rejections
- repl:
  - improve require() autocompletion
- src:
  - add openssl-system-ca-path configure option
  - add --use-bundled-ca --use-openssl-ca check
  - add process.ppid
- tls:
  - accept `lookup` option for `tls.connect()`
- tools, build:
  - a new macOS installer!
- url:
  - WHATWG URL api support
- util:
  - add %i and %f formatting specifiers


(fhajny)