Update lang/nodejs to 7.3.0.

Notable changes

buffer:
- buffer.fill() now works properly for the UCS2 encoding on
  Big-Endian machines.

cluster:
- disconnect() now returns a reference to the disconnected worker.

crypto:
- The built-in list of Well-Known CAs (Certificate Authorities) can
  now be extended via a NODE_EXTRA_CA_CERTS environment variable.

http:
- Remove stale timeout listeners in order to prevent a memory leak
  when using keep alive.

tls:
- Allow obvious key/passphrase combinations.

url:
- Including base argument in URL.originFor() to meet specification
  compliance.
- Improve URLSearchParams to meet specification compliance.

(fhajny)