Add missing library dependency

cmr:v1.7.3:reviewer=jsquyres

Do some cleanup of the way we handle modex data. Identify data that needs to be shared with peers in my job vs data that needs to be shared with non-peers - no point in sharing extra data. When we share data with some process(es) from another job, we cannot know in advance what info they have or lack, so we have to share everything just in case. This limits the optimization we can do for things like comm_spawn.

Create a new required key in the OMPI layer for retrieving a "node id" from the database. ALL RTE'S MUST DEFINE THIS KEY. This allows us to compute locality in the MPI layer, which is necessary when we do things like intercomm_create.

cmr:v1.7.4:reviewer=rhc:subject=Cleanup handling of modex data