geant-vmc-9999: Make "test" really work, some doc-related fixes. 

Fix doxygen-generation, adapt to now working way to run the test-suite (patched upstream), it was broken before (e.g. return code was always zero). 

I have created patches for upstream which are now applied and allow to build the examples (necessary for test-suite) without installing them - also, the tests work pre-installation now (and several other test-related issues were fixed).