[patches] introduce patch for dune-grid 2.3.1

The patch allows using the multidomain models together with a UG library
that has been compiled for parallel usage. Most likely, the patch will
make its way to dune-grid and should not be needed anymore from
dune-grid 2.4.

Approved by natalies.



git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@13501 2fb0f335-1f38-0410-981e-8018bf24f1b0