GitLab

Due to recently introduced "use mpi" statements also some
naming conflicts have been introduced. It seems to be the case
that some MPI libraries use the name "mpi_comm". I therefore replaced
variables with that name in fleur by "fmpi_comm". I don't know
whether I found every place where this problem is present. Please
perform similar replacements if you find more places.

This reverts commit f5fe58e8.

The error message also prints out labels of overlapped
atoms (one of the labels) and the overlapping value.
The error message makes AiiDA-FLEUR to conviniently
parse this info and automatically adjust MT radii
for another try of relaxation.

Based on v0.26 hybrid branch