I should work on a specific FiniteElement class or FEM for blockstructuring, s.t. I can remove the element parameter from the blockstructured implementation as well.

Computes tensor index from single index.

Moves application of transformation from micro to reference element from visitor to PDELab interface

Removes micro_to_macro_index from accum_insn and introduces a class BlockstructuredAccumulationSpace to specialize AccumulationSpace for blockstructured FEM

It was the wrong level of asbtraction!