- version with weights in the entropy denominator

- possbility for custom ast nodes (debugging)
- support for fields in boundary condition

- boundary handling more flexible now: boundaries return LIST of equations now
- new pressure boundary

and not as a string.
Changed name of the file TypedSymbol to types.
Fixed usage of dtype accordingly, however i might not have found every
usage of dtype.

- new waLBerla only benchmark

- wrote a new, separate lattice model for cumulants
- tested with 2D LDC

- new testcase & notebook for simplifications

- fallback to no caching if joblib is not available

- loading waLBerla and waLBerla_grandchem in the same script leads to problems
 this happened during pytest (doctests) -> put imports inside functions

problem in moveConstantBeforeLoops transformation:

--> a should end up here
{
for() {
  const int a = 5;
}
for() {
  const int a = 5
}
}

the "a" of the lower loop was not moved up, since it could not move across first loop (which is wrong)

- LoopOverDomain changed to be able to loop over rectangular sub-region of field
- support for slicing with makeSlice