In particular this means having to carry mappers for the local indices around.
This makes the code more verbose, but it also makes it easier to see what is
happening.  While coding this stuff I keep having doubts about whether all
the renumbering works correctly...

[[Imported from SVN: r9925]]

The global indexing infrastructure does not currently support P3 spaces.

[[Imported from SVN: r9924]]

[[Imported from SVN: r9923]]

The local copy was to get the thing developed and working.  Now that it is
working we upstream it into dune-grid.

[[Imported from SVN: r9922]]

The IndexSet interface class from dune-grid doesn't have it, and we want
to be like the interface method as much as possible.

[[Imported from SVN: r9921]]

[[Imported from SVN: r9920]]

That's what this method is called in the dune-grid IndexSet
interface.

[[Imported from SVN: r9919]]

[[Imported from SVN: r9918]]

[[Imported from SVN: r9917]]

Yes it is to be moved to dune-grid, but for the transition it is
easier to use the one from this module.

[[Imported from SVN: r9916]]

[[Imported from SVN: r9915]]

[[Imported from SVN: r9914]]

[[Imported from SVN: r9913]]

[[Imported from SVN: r9912]]

That code was written back in the days when we were only using
first order spaces.  Now, with other spaces, we have to properly
distinguish between grid vertices and Lagrange nodes.

[[Imported from SVN: r9911]]

[[Imported from SVN: r9910]]

[[Imported from SVN: r9909]]

Use MPIHelper instead.

[[Imported from SVN: r9908]]

[[Imported from SVN: r9907]]

[[Imported from SVN: r9906]]

[[Imported from SVN: r9905]]

[[Imported from SVN: r9904]]

[[Imported from SVN: r9903]]

[[Imported from SVN: r9902]]

[[Imported from SVN: r9901]]

[[Imported from SVN: r9900]]

[[Imported from SVN: r9899]]

As of yet completely untested

[[Imported from SVN: r9898]]

[[Imported from SVN: r9897]]

The implementation uses TinyXML2.  If you don't have that installed
then a NotImplemented exception will be thrown.

The code is still pretty fragile, and needs more defensive programming.
It will probably crash on a number of well-formed files.

[[Imported from SVN: r9896]]

[[Imported from SVN: r9895]]

[[Imported from SVN: r9894]]

It is not used anymore.  On the other hand, I want to get rid of 
GeometryGrid in the CosseratVTKWriter.  Now with the new VTKFile
at hand there is a chance.

[[Imported from SVN: r9893]]

[[Imported from SVN: r9892]]

[[Imported from SVN: r9891]]

[[Imported from SVN: r9890]]

[[Imported from SVN: r9889]]

[[Imported from SVN: r9888]]

This is needed for projection-based finite elements.

The code in this patch has not been tested yet.

[[Imported from SVN: r9887]]

[[Imported from SVN: r9886]]