Sandia OpenSHMEM v1.2.0

• Support for OpenSHMEM 1.2 specification
• Support for Open Fabric Interfaces (OFI) libfabric
• Integrated support for PMI-1 compliant launcher (e.g. MPICH Hydra)
• Build now generates 'oshrun' launcher script for launching OpenSHMEM applications
• Multiple bug fixes and improvements to stability and performance
• Add shmemx.h and shmemx.fh header files for Sandia OpenSHMEM extensions
• Add support for short, SGI-style Fortran header (configure option
  --disable-long-fortran-header) required by UH test suite
• Removed stale copies of UH tests, upstreamed changes, and moved to external
  testing model. Extensive bug fixes and improvements to remaining test suite.