[cornerpoint] Fix test and fluxvariables. Adapt to Opm 2015.10.

- Add a missing } in the test cc file.
- Add Dune::Geometries to CpFVElementGeometry.
- Fix the boundary transmissibilities.
- Change call to Opm parser routine to be compatible with Opm 2015.10.
- Adapt patches to Opm 2015.10.