Default binding in heterogenous bindings is weird

[jsquyres]

We default to "bind to socket" and if the sockets aren't all homogeneous, OMPI doesn't handle this properly.

Reported by Marcin Krotkiewski here: http://www.open-mpi.org/community/lists/users/2015/10/27770.php

@rhc54 has told @ggouaillardet how he thinks it should be solved (and @rhc54 is mostly unavailable for another week or three)

[jsquyres]

Discussed on the 2015-10-20 webex; the feeling is that this may be too big to pull back to the v1.10.x series, and the fix will likely be in the 2.x series.

[hppritcha]

Kicking down the road to 3.x

[bwbarrett]

Given that this lived through the entire 2.x series, it's clearly not a blocker for 3.0. Punting to the future.