Write Exodus files in netCDF-4 format when HDF5 is available.
Write Exodus files in netCDF-4 format when HDF5 is available.

This seems to work even in the relatively old (v5.22) version of
Exodus that we currently distribute with libmesh, nevertheless it
would be good to update to a more recent version of Exodus [0] at some
point.

[0]: The master branch of https://github.com/gsjaardema/seacas comes
     with Exodus v7.14.

BalticPinguin/libmesh,roystgnr/libmesh,BalticPinguin/libmesh,capitalaslash/libmesh,90jrong/libmesh,pbauman/libmesh,hrittich/libmesh,pbauman/libmesh,libMesh/libmesh,libMesh/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,hrittich/libmesh,BalticPinguin/libmesh,hrittich/libmesh,jwpeterson/libmesh,pbauman/libmesh,libMesh/libmesh,capitalaslash/libmesh,dschwen/libmesh,capitalaslash/libmesh,dschwen/libmesh,90jrong/libmesh,90jrong/libmesh,jwpeterson/libmesh,dschwen/libmesh,90jrong/libmesh,pbauman/libmesh,roystgnr/libmesh,pbauman/libmesh,capitalaslash/libmesh,roystgnr/libmesh,dschwen/libmesh,hrittich/libmesh,libMesh/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,dschwen/libmesh,roystgnr/libmesh,dschwen/libmesh,pbauman/libmesh,hrittich/libmesh,libMesh/libmesh,90jrong/libmesh,roystgnr/libmesh,hrittich/libmesh,roystgnr/libmesh,libMesh/libmesh,libMesh/libmesh,hrittich/libmesh,pbauman/libmesh,90jrong/libmesh,BalticPinguin/libmesh,90jrong/libmesh,jwpeterson/libmesh,roystgnr/libmesh,90jrong/libmesh,BalticPinguin/libmesh,hrittich/libmesh,pbauman/libmesh,90jrong/libmesh,capitalaslash/libmesh,capitalaslash/libmesh,BalticPinguin/libmesh,hrittich/libmesh,roystgnr/libmesh,capitalaslash/libmesh,capitalaslash/libmesh,jwpeterson/libmesh,dschwen/libmesh,libMesh/libmesh,pbauman/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,dschwen/libmesh