update to DUNE v2.5.1
This makes DORiE compatible to DUNE v2.5.1, which is contained in the
releases/2.5 branches as before.
dune-pythonpackage was removed as dependency, since its functions have been moved to
dune-common. This changed some of the CMake interfaces for Python calls.
dune-testtoolsversion has been bumped to
master, since its
releases/2.5branch has not been updated yet.
- legacy UG grid is not supported anymore
- recommending Python 3 for all setups
- revisited README