doc: fix net.Server.listen bind behavior

[zertosh]

2272052 changed net.Server.listen's behavior so that when the bind address is omitted, IPv6 is tried first and IPv4 is used as a fallback.

Also, added the note about the random port to http and tls, since that's true for them too but only net mentioned it. And, changed the argument name to hostname for net and tls because, although it's not named in listen, that argument is eventually passed to dns.lookup and it calls it hostname (plus http already called it that).

[rvagg]

+1 from me but it'd probably be good to be explicit about what :: and 0.0.0.0 do like in the original docs and spell out that they accept connections on "any IPv6" and "any IPv4" addresses respectively.

[zertosh]

@rvagg How's the wording now?

Also, this change in net didn't make it to the changelog's "Summary of changes from Node.js v0.10.35 to io.js v1.0.0" - in fact, there isn't even a net section. Should I add a quick entry? Something like "Changed net.Server.listen's behavior such that, when the bind address is omitted, IPv6 is tried first, and IPv4 is used as a fallback."

[rvagg]

@zertosh yes, this looks good to me

@indutny can you confirm that this doc matches the new behaviour? (I don't really want to take sole responsibility for the doc change)

@zertosh: best to open a separate PR to change/add to the changelog, but +1 on that, we've had a few additions to that section since 1.0.0.

[rvagg]

Landed @ 5c7ab96, in future @zertosh can you make sure you push as a single commit instead of spanning multiple commits (I think the CONTRIBUTING.md doc mentions this). Thanks!

[zertosh]

@rvagg sorry, I meant to squash the commits. I'll make sure to keep it in mind