New vectorization features

See merge request dominic/dune-perftool!227

It would be hard to implement on top of the latest feature and contradict
features projected for the near future.

Generate adjoint and control operators

See merge request dominic/dune-perftool!223

enables use of permute and [] in opcounter

See merge request dominic/dune-perftool!231

fixes a nasty bug, where face information was omitted

By implementing repr such that instance addresses are
not part of sorting anymore

Make order of assembly methods deterministic

See merge request dominic/dune-perftool!230