MeshInput::is_parallel_format() accessor
MeshInput::is_parallel_format() accessor

This makes it easier to write generic tests that work with both
Nemesis and Exodus

roystgnr/libmesh,roystgnr/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,libMesh/libmesh,roystgnr/libmesh,dschwen/libmesh,jwpeterson/libmesh,roystgnr/libmesh,libMesh/libmesh,libMesh/libmesh,roystgnr/libmesh,jwpeterson/libmesh,dschwen/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,dschwen/libmesh,libMesh/libmesh,dschwen/libmesh,dschwen/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,libMesh/libmesh,libMesh/libmesh,dschwen/libmesh,jwpeterson/libmesh,dschwen/libmesh,libMesh/libmesh,BalticPinguin/libmesh,dschwen/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,libMesh/libmesh,jwpeterson/libmesh