This new test computes a harmonic map from a square to a sphere.
In other words, rather than testing some specific aspect of some
class, it does a whole simulation.  It should therefore cover
much more of the dune-gfe code.

I wrote it without a clear idea of what is needed of such a
test function, and I never finished it.  Now it is unclear
what the code does or is supposed to do, so let's just
remove it.

In particular, we move the test for the computeDR method from
cosseratenergytest.cc to here.  It is a method that does not
have anything to do with Cosserat mechanics directly.

The test still seems overly complicated.  Do I really need
a LocalGeodesicFEFunction?  Maybe I can simplify it later.

It's not clear what it is supposed to be testing at all.

It is no test.  Rather, it is a program I used to create illustrations
for the paper on GFE test functions (arXiv:1607.07479).  I moved the
program into the git repository of that paper.

This was never a real test.  Rather, it was I toy for me to test
a mathematical property of GFE functions which is known to be
false anyway.