Depending on the Dune version, the boundary markers are present on
all processes (<= 2.6) or on the root process only (>= 2.7). Try to
handle this in a flexible way in the corresponding data handle:
Determine if the minimum size over all processes of the boundary
markers vector is zero. If yes, assume that the root process contains
all markers and broadcast them.

Currently, it isn't possible to refine a parallel UGGrid that has
been read by a GmshReader, see dune-grid issue #83. Therefore, don't
refine in the corresponding test.

[fix] Exception is not allowed in constepxr function

See merge request !1383

Feature/mpfa-scv-gradient-reconstruction

See merge request !1325

Feature/test facetcoupling xi

See merge request !1283

Dennis Gläser authored 6 years ago and Timo Koch committed 6 years ago

this jump should be independent of the choice for xi, which is why
here we test if for different values of xi the same reference solution
is obtained.

[mp] Streamline interface for MP material laws

See merge request !1376

[boxdfm][vtk] store pointer to fracture grid

Closes #629

See merge request !1378

[freeflow] Remove TypeTag from FluxOverSurface

See merge request !1380

Remove unused memeber variable virtualOuterNormalFaceDofPos from pairData.

See merge request !1379