[dune-pdelab] DiscreteGridFunction of PowerGridFunctionSpace

[Christian Engwer]

Hey,

I'm trying to implement a DG Stokes code based on PDElab, which will
serve as a starting point for a transition of my UDG Code to PDELab.

Today I managed to implement the block-structure stuff in pdelab and
now I can create a function space like this:

v \in P_k
p \in P_{k-1}

V_{stokes} = (P_k)^d \times P_{k-1}

Using the sub-space stuff it is quite easy to create a scalar discrete
function for the pressure. But when I try to create a vector valued
discrete function for the velocity (PowerGridFunctionSpace<DG-K-Space,dim>)
I get some errors about missing typedefs in some traits etc.

- Did anybody successfully create vector valued discret functions?
- What is the trick?

Christian

PS: did I mention, that we definitely have to improve the
	documentation?