OS-4525: lxbrand implement getsockopt(TCP_INFO)

[cneira]

Hi,
This change adds TCP_INFO option to LX branded zones here is the diff required TritonDataCenter#459.

Let me know if more changes are required, but I tried just fill up, the current fields used by apps

[oetiker]

can you create a PR?

[cneira]

@oetiker Here is the current change that was merged into SmartOS, I'll try to make a PR but it gets more complex if you have illumos-joyent and illumos-omnios repos.
TritonDataCenter@80cb3c4