[dune-fem] P1+bubble and P1 not conforming

[Andreas Dedner]

Hi Marco.
The mini space is now used within the dune-fem-howto and
it is quite easy (I think) to see how to modify that for a
not conforming space.
Check out the stokes branch of the dune-fem-howto and look
at example-space and example-stokes.

The stokes problem in that branch of the howto
does not yet compile correctly because there is a patch for the
IndexSetMapper that I haven't yet added to dune-fem.
I wanted to discuss if that fix is the "best" (it's about getting
rid of LagrangePointSets in the Constraints). I'll simply push
it to master tomorrow since it's not intrusive.
Andreas

PS:
We already said that we should meet and since we are working
on similar things that's doubly true. I'm leaving for a vacation
on Friday for 2 weeks so meeting before that is probably a bit
difficult. How free are you to meet in August?