Don't create targets for tests,tutorials, benchmarks if they are disabled in CMake
Currently the make targets for tests, tutorials, benchmarks and showcases are created even if e.g. WALBERLA_BUILD_TESTS
but they are excluded from the all
target.
This way they can still be build when calling directly. However it clutters the targets in e.g. an IDE.
I suggest we remove the targets entirely when they are disabled.
Opinions?
Edited by Dominik Thoennes