Per the RFC schedule, this commit adds Mellanox OpenSHMEM to the trunk. It does not yet run on OSX or with CM PML for an MTL other than MXM. Mellanox is aware of these issues and is in the process of resolving them. This should be added to \ncmr=v1.7.4:subject=Move OSHMEM to 1.7.4:reviewer=rhc