Update DUNE_PYTHON_WHEELHOUSE on change of CMAKE_INSTALL_PREFIX
Summary
The cmake cache variable DUNE_PYTHON_WHEELHOUSE
defaults to ${CMAKE_INSTALL_PREFIX}/share/dune/wheelhouse
. If CMAKE_INSTALL_PREFIX
is set after the first cmake run, this default is not updated. This MR fixes this issue by an additional variable that is set to DUNE_PYTHON_WHEELHOUSE
if given by the user, otherwise falls back to the default path. This new variable DUNE_PYTHON_WHEELHOUSE_DIR
is not a cache variable and thus updated every cmake run.
Closes #339 (closed)