Add support for local addresses in BTL TCP

[bosilca]

Cherrypick 93fa94f.

[jsquyres]

@hppritcha Will do in the next day or so.

[hppritcha]

just a heads up that this commit does not apply cleanly to v2.0.x nor to v2.x.

[hppritcha]

this is a mess. it looks like we also need commit from #2054, maybe more.

[jsquyres]

@hppritcha @bosilca Might I suggest that we simply defer this to v3.0.0 -- would that be ok?

[bosilca]

👍

[bwbarrett]

This patch is in 3.0.x and 3.1.x, so not sure why we left this issue open. Closing.