doc: improve http.request and https.request opts

This adds a few previously undocumented option to both functions.

PR-URL: https://github.com/iojs/io.js/pull/1551
Fixes: https://github.com/iojs/io.js/issues/1082


Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>