Do not overwrite NETGEN_VERSION that might be cached. Use a new variable instead, NETGEN_VERSION_C. Use cmake internal system to specify std=c++14, else you can end up with `c++ -DFOO -std=c++14 -Ibar -std=c++11`, and the latter is used.
Do not overwrite NETGEN_VERSION that might be cached. Use a new variable instead, NETGEN_VERSION_C. Use cmake internal system to specify std=c++14, else you can end up with `c++ -DFOO -std=c++14 -Ibar -std=c++11`, and the latter is used.