Needs a small fix in loopy (MR opened).

It is a memory reinterpretation

... instead of reimplementing it all over the place

They are concepts that are not really necessary with local
storage, that I do not really want to explain to other people.

Only register generators globally. This makes inspection of cache
items much easier.

Some work on parameter classes, a bugfix on the splitting algorithm
some simplifications in the generation stage

as a consequence introduce template parameters

laplace is again proceeding to code generation

much more clever!