[bugfix] Fix Vectorbackends for scalar problems

See merge request dominic/dune-perftool!193

Feature/no overlap assembly

See merge request dominic/dune-perftool!191

To ensure that all partitions have exactly the same size!

Which play well with the latest change to not assemble on the overlap.

Heuristic vectorization strategy

See merge request !190

We mistook a tag for an Id here...

It always aims for maximally horizontal vectorization
where possible.

Fixup sum factorization of maxwell

See merge request !188

Beautify the conditional handler

See merge request !187

The previous changes to directly pass the visitor
into the coefficient handler was messed up in one place
- only being triggered by the downstream maxwell example.

So far, it had to restore indexing information on the visitor
for the second branch. This can be avoided by index pushdown,
just as we do with the sum of two tensors.

Feature/fixes for dimitri

See merge request !184

Remove dune-geometry patch

Closes #102

See merge request !186

It is obsolete on latest master.

When doing jacobians of nonlinear systems, the inames used for
a given sum factorization kernel output depend on the accumulation
context.

Otherwise debugging of nonlinear problems becomes hard.

We havent got a nonlinear sumfact test case so far, so this one did not break.
test coming soon.

It spares us some hassle with function manglers.

Feature/stokes application cherrypick

See merge request !182

By using loopys group mechanism. Each sum factorization kernel
defines a group that conflicts with all other sum factorization
groups.

Conflicts:
	python/dune/perftool/sumfact/realization.py
	python/dune/perftool/sumfact/vectorization.py