Figure out where the closest dune.module is, and parse it for
information. The defines are added to config.h, so that our code
may behave differently for various versions available.
It actually works for opm-core 1.0 as well, but don't tell anyone;
we rather want people to use opm/core/version.h instead.
If a module has been backported and installed to a directory which
also contains the version number, e.g. /usr/include/dune-2.3, to
avoid clashing with an existing version in /usr/include, then this
part is now stripped from the include directory and added back to
the lib directory where we are looking for dune.module
