Notable changes:

* npm: Upgrade to v2.15.1. IMPORTANT: This is a major upgrade to npm
  v2 LTS from the previously deprecated npm v1. (Forrest L Norvell)
* npm: Upgrade to v2.15.1. Fixes a security flaw in the use of
  authentication tokens in HTTP requests that would allow an attacker
  to set up a server that could collect tokens from users of the
  command-line interface. Authentication tokens have previously been
  sent with every request made by the CLI for logged-in users,
  regardless of the destination of the request. This update fixes this
  by only including those tokens for requests made against the
  registry or registries used for the current install. IMPORTANT:
  This is a major upgrade to npm v2 LTS from the previously deprecated
  npm v1. (Forrest L Norvell) https://github.com/nodejs/node/pull/5967
* openssl: OpenSSL v1.0.1s disables the EXPORT and LOW ciphers as they
  are obsolete and not considered safe. This release of Node.js turns
  on `OPENSSL_NO_WEAK_SSL_CIPHERS` to fully disable the 27 ciphers
  included in these lists which can be used in SSLv3 and higher. Full
  details can be found in our LTS discussion on the matter
  (https://github.com/nodejs/LTS/issues/85).
  (Shigeki Ohtsu) https://github.com/nodejs/node/pull/5712

PR-URL: https://github.com/nodejs/node/pull/5968