Use const references where necessary.

Rename a the method from getNumberOfComponents() to getNumberOfGlobalComponents()
in class LocalToGlobalIndexMap.

The fmt library happily accepts std::string without
any conversions.

Fixes multiple copyright messages in the doxygen docu.

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

Adding a new function for parameter lookup of optional tags.

This reverts commit d825ea54.

Also add default initialization where needed.

See previous commit for details.

Clang format run on near-the-header lines.

Happy New Year

Store the results in the process data.