film-on-substrate uses a class of dune-elasticity that is not available in earlier versions

In 3D and for second order elements the globaldofmapper from dune-parmg is needed.

It combined computing rod configurations and their discretization
errors.  Nowadays the way to do that is to use rod3d.cc for the
rod configurations, and compute-disc-errors.cc for the errors.
Hence rod-eoc.cc is not needed anymore and can go.

These two files are very similar, and merging them will reduce
maintenance effort in the future.  As of this patch, there is
now quite a number of preprocessor directives in the new merged
cosserat-continuum.cc.  That is not pretty, but the new state
is still much easier to maintain than two completely separate
files.  What is more, I hope to be able to reduce some of that
preprocessor trickery by smarter use of the dune-functions
basis trees.

In many cases it is not needed, but I am too lazy to write
a proper test for it right now.

It is so uncompileable that I am not able to fix it quickly.  Since I don't
actually need it right now I let it wait for another day.

This initial commit simply brings a cleaned-up version of the harmonicmaps program.
The first step will be to make it compute curve-shortening flow on the sphere.

Here is a new program that does nothing but compute discretization errors:
that is L2 and H1 norms of differences between two functions.  The reference
function can be either discrete or given in closed form (the latter is not
enabled yet).

So far I have only used this program to measure discretization errors of
Cosserat shell models, and I did *not* get the error behavior I expected.
So either the error behavior of such shells is weird, or this new measurement
program is still buggy.

It was only in the dune-gfe module for historic reasons.

[[Imported from SVN: r10095]]

While we are there, set all the flags in a loop, so we don't have
to keep copying boilerplate code as the number of programs to build
increases.

[[Imported from SVN: r10074]]

[[Imported from SVN: r10061]]