Created output paths are then consistent with Linux / macOS.
Switched from deprecated CMake variables to newer ones.

Try to speed up release stage.

Suffixes are added for specific configs:

-de    for OGS_BUILD_GUI
-utils for OGS_BUILD_UTILS
-mpi   for OGS_USE_MPI

Can be forced by setting OGS_32_BIT=ON

Ancient CMake versions required upper-case commands. Later command
names became case-insensitive. Now the preferred style is lower-case.

Run the following shell code:

cmake --help-command-list |
grep -v "cmake version" |
while read c; do
    echo 's/\b'"$(echo $c | tr '[:lower:]' '[:upper:]')"'\(\s*\)(/'"$c"'\1(/g'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed

This copies all file from ${CMAKE_SOURCE_DIR}/../ogs6-data to
/data/ogs/ogs6-data and then triggers a build on Jenkins which
syncs /data/ogs6-data to opengeosys.org

Replace CMAKE_SOURCE_DIR with CMAKE_CURRENT_SOURCE_DIR and
CMAKE_BINARY_DIR with CMAKE_CURRENT_BINARY_DIR. This allows to use
OGS as a subdirectory in another project.

logog header files have to be included e.g. with logog/include/logog.hpp

This fixes #27.

Grouped logog targets.