This commit adds an option that allows to enable detecting parallel
logging fallout (option --enable-logging-fallout-warning). It is now
false by default (previous behavior was as if the option was true).
If option is true a warning will be printed for any process with nonzero
rank that does try to log to *.PRT or *.DBG and the logged output will be appended
to these files at the end.
Previously the regex issued warning for all files containing ".[0-9]*." in the name
in the output directory. That was too general and created more warnings than we wanted.
The regex we are using might also consider a file named bla.2.blub.
In that case it is not nice to throw an exception. Instead we print
a message to std::cerr.
This is currently still happening due to the implementation of
OPM_THROW whenever the linear solver does not converge. This
happens quite often and we might not want to get overwhelmed by
the issue tracker.
