Cosserat-Continuum-Nonplanar

@osander: Can you have a look here?

This MR cleans up the usage of MIXED_SPACE in cosserat-continuum.

Now all combinations of dim = dimworld or dim != dimworld and MIXED_SPACE = 0 or MIXED_SPACE = 1 at least compile.

Also, this MR points out the one combination that still can't be solved: Problems with dim != dimworld do not work for MIXED_SPACE = 1!

As soon as I need this for locking tests I will add this; I will have to change Nonplanarcosseratshellenergy so it can be assembled with the GFEMixedAssembler.

src/CMakeLists.txt

 set(programs compute-disc-error
              cosserat-continuum
              gradient-flow
-             harmonicmaps
-             rod3d)
+             harmonicmaps)
 #            rodobstacle)
 
+if (NOT dune-vtk_FOUND)
+  set(programs rod3d ${programs})
+endif()
+
 if (${DUNE_ELASTICITY_VERSION} VERSION_GREATER_EQUAL 2.8)
   set(programs film-on-substrate-stress-plot ${programs})
 endif()