Add external component to opal/pmix framework

[rhc54]

Need an external component to allow packages to link against external libpmix

[hppritcha]

Is this an enhancement or a bug? Why should an enhancement be a blocker for 2.0 release?

[rhc54]

@hppritcha The upstream packagers require it before they will include OMPI 2.0 in their packages.

[hppritcha]

Okay, so they don't want to use the pmix1xx, but rather a version of the standalone pmix?

[rhc54]

Yeah, they don't like embedded packages. This is why we now have support for external libevent and hwloc as well. Basically, any package that is also available on its own has to be externally linked even if we have an internal version as well.

[hppritcha]

@rhc54 is this something you can get to in the next week or two? Or would it be okay for this to wait till a post rc1 for 2.0.0?

[rhc54]

@hppritcha I think @igor-ivanov et al have got this in reasonable shape, but we are still wrestling with the libevent duplicate symbol question. So I'd say push to post rc1 is fine