This are all but backward Euler.
The few testcases in H2-pp were updated to backward Euler
without loss of accuracy.

 - All processes using a Newton scheme are discretized
for the backward Euler scheme only. They are not usable
with other time discretizations.
 - Greatly simplifies code maintenance in this part.

Avoid local variables `process_id' when looping over
all processes.
Move numbering of the processes to the ProcessData ctor.

Fixes multiple copyright messages in the doxygen docu.

ag '\\file' -L --ignore=ThirdParty *Lib |xargs  sed -i 's/\(.*\)\\copyright/\1\\file\n\1\\copyright/'

This seems to be unused. At least the current benchmarks
do not need this special cases.

Dmitri Naumov authored 5 years ago and Tom Fischer committed 5 years ago

The name is already included in the process.

It contains a boolean for met error norms and a
number of iterations of the solver made.

The number of iterations is needed for
a timestepping scheme.

If 'old' prj-file is used abort with OGS_FATAL.

Also update the variables' names and some of the docu.