add mpi support to meme (#4265)
add mpi support to meme (#4265)

* added openmpi support to meme

* openmpi is a link dependency which leverages r_path

* openmpi support now the default - meme does not have configure argument for mpi - if it's found then it's used

* added serial option and set mpi to not be default

* modified meme

TheTimmy/spack,LLNL/spack,mfherbst/spack,LLNL/spack,tmerrick1/spack,TheTimmy/spack,skosukhin/spack,skosukhin/spack,krafczyk/spack,tmerrick1/spack,iulian787/spack,EmreAtes/spack,krafczyk/spack,skosukhin/spack,iulian787/spack,iulian787/spack,EmreAtes/spack,matthiasdiener/spack,tmerrick1/spack,mfherbst/spack,EmreAtes/spack,matthiasdiener/spack,mfherbst/spack,TheTimmy/spack,tmerrick1/spack,krafczyk/spack,tmerrick1/spack,iulian787/spack,LLNL/spack,EmreAtes/spack,EmreAtes/spack,krafczyk/spack,matthiasdiener/spack,mfherbst/spack,skosukhin/spack,matthiasdiener/spack,iulian787/spack,lgarren/spack,lgarren/spack,matthiasdiener/spack,skosukhin/spack,krafczyk/spack,LLNL/spack,lgarren/spack,lgarren/spack,TheTimmy/spack,mfherbst/spack,TheTimmy/spack,LLNL/spack,lgarren/spack