Searching for optional submodules has to be actively enabled by this
option. This prevents unexpected CMake errors when developers checked
out the submodules without their knowledge (as it happens e.g. with
the Windows GitHub app).

Using logog in GeoLib and removing some include dependencies

This fixes #71.

Mesh2 mesh property interpolation

Conflicts:
	GeoLib/Raster.cpp
	GeoLib/Raster.h

Fixed link on front page README.md

replaced ufz.github.com with
devguide.opengeosys.org

Before also necessary tools were not searched for.

Enables configuration of uncrustify pre-commit-check.

Uncrustify is a source code beautifier. Enabling this via scripts/init.sh runs uncrustify before commit on the changed files and *suggests* changes to the code to be conform with the style guide.

This should enforce a common code style and reduce number of white-space changes and also improve the readability of the code.

Using logog in MeshLib.

Replace all of std::cout std::cerr.

System of linear equations inteface and Lis solver interface.

In case delta is really zero, set it to a small value to omit division by zero.