New implementation of MillingtonQuirk can lead to different solution
When using the new implementation for the Millington Quirk effective diffusivity the solution can be different. E.g. in co2plumeshape exercise in dumux - lecture. The old implementation used pow(sw phi, 7/3) the new implementation to avoid pow uses a cubicroot. See commit 7b864375056ec92d7b6250bc25b0b3ab0fa4329 for details.