With that change "Volumetric"/"Python" source terms can be applied to nodes, as well.
Thereby, the special "Nodal" source term has become obsolete, now.

This allows the function to be called from outside,
given the GlobalDim template parameter is known.

Include spdlog via BaseLib/Logging.h, which
provides macro replacements for
ERR/DBUG/WARN/INFO...

Fixes multiple copyright messages in the doxygen docu.

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

Clang format run on near-the-header lines.

Happy New Year

This slightly reduces included amount of code.

Creation of local assemblers belongs to the processes.