fix missing mpi.h include for h5readatt_octave.cc

Signed-off-by: Thorsten Liebig <thorsten.liebig@gmx.de>
nf2ff: calculate LH- and RH circular polarization

Signed-off-by: Thorsten Liebig <thorsten.liebig@gmx.de>
examples: dipole antenna example update

Signed-off-by: Thorsten Liebig <thorsten.liebig@gmx.de>