[config.h] silence HAVE_MPI -Wundef
[common.disable_warnings] added some to clang

* -Wshorten-64-to-32
* -Wmismatched-tags
* -Woverloaded-virtual
* -Wfloat-equal
* -Wnon-virtual-dtor
[common.math] added missing config.h include
silenced some external warnings
[grid.provider.cube] added supprt for new alugrid names