Update lang/nodejs to 5.7.1.

* path.relative():
  - Output is no longer unnecessarily verbose
  - Resolving UNC paths on Windows now works correctly
  - Resolving paths with prefixes now works correctly from
    the root directory
* url: Fixed an off-by-one error with parse()
* dgram: Now correctly handles a default address case when offset
  and length are specified (Matteo Collina) #5407.

Irrelevant to (dynamically linked) lang/nodejs:

* openssl: Upgrade from 1.0.2f to 1.0.2g

(fhajny)