Mostly in the file headers.

find *Lib -type f | xargs sed -i 'N;s%^\s\+\*\n\(\s\+\*/\)%\1%'

If only file name is specified it causes a warning
about the name not to be specific enough if there is
another file with the same name, e.g.:

the name `IdealGasLaw.h' supplied as the second argument
in the \file statement matches the following input
files: ogs/MaterialLib/Fluid/Density/IdealGasLaw.h
ogs/MaterialLib/MPL/Properties/IdealGasLaw.h
Please use a more specific name by including a (larger)
part of the path!

From now on only \file w/o a name or a full path will
be allowed.

find -type f | xargs sed -i 's%\(\\file\).*%\1%'

Clang format run on near-the-header lines.

Happy New Year

This reverts commit 05677165.

Conflicts:
	FileIO/XmlIO/XmlGspInterface.cpp
	README.md

- added test programm for solving a linear system with CG-method
- time measurement is at the moment OS dependent!
- added Base folder
- added GeoLib folder
- added files in MathLib folder - restructured MathLib folder

- applying changes to interfaces