Due to backwards compatibility dns.js is reporting UV_EAI_MEMORY, UV_EAI_NODATA, and UV_EAI_NONAME errors as ENOTFOUND

This is currently labelled FIXME --> https://github.com/nodejs/node/blob/master/lib/dns.js#L17-L23

ENOTFOUND is not even a proper POSIX error!
@bnoordhuis

The change breaks a few tests

• test-http-dns-error
• test-net-better-error-messages-port-hostname
• test-net-connect-immediate-finish
• test-net-dns-error

interestingly enough every testc ase we had was for EAI_NONAME, we have no tests for EAI_MEMORY or EAI_NODATA

If people are interested I'll get started on this change, including writing extra tests and smoke testing. This should be a great candidate for citgm