* provide a more reliable way of determining that a process is a singleton by leveraging the schizo framework. Add new components for slurm, alps, and orte to detect when we are in a managed environment, and if we have been launched by mpirun or a native launcher. Set the correct envars to control ess and pmix selection in each case.
* change the relative priority of the pmix120 and pmix112 components to make pmix120 the default
* fix singleton comm-spawn by correctly setting the num_apps field of the orte_job_t created by the daemon - this fixes a segfault in register_nspace on newly created daemons
* ensure orterun doesn't propagate any ess or pmix directives in its environment
* Cleanup a few valgrind issues and memory leaks
* Fix a race condition that prevented the client from completing notification registrations (missing thread shift)
* Ensure the shizo/alps component detects launch by mpirun
Cleanup the configury so we properly check for Singularity under the various typical use-cases
Bring the Singularity support online. We have to turn "off" the sm BTL as it segfaults from inside the container - root cause remains unclear. Also turned "off" the various OPAL shmem components in case they are involved and someone else tries to use them. Happily, the vader BTL works just fine!
