These are not aware whether they are parallel or not. Therefore
the user should only specify a verbose verbosity only on one rank.
With this commit we do this on the process responsible for terminal
output.
In upstream they expect to be used with FielMatrix as
the block type only. Thus it it is impossible to use AMG
with a direct coarse solver within OPM. With this patch
it would be possible if we did not use field type float.
