+ adjust test accordingly

This fixes a segfault, since after a copy of the space the backend_ would
still hold a reference to the grid_part_ of other which is not guaranteed
to still exist. Thus we would need to make a copy of backend_ (not possible
with dune-fem) or create a new backend_ (which would mathematically
hopefully be a copy, but we do not know about dune-fems internals so we can
not be sure) or again hold a shared_ptr of the backend_ and the grid_part_
and the grid_view_, which I opted for.

refs #13
currently breaks a few copy tests

refs #13
currently breaks FemBased Spaces testing due to GridPart/View types
snafu

This should ensure that all spaces have a sane copy and move ctor and
forbid copy and move assignment. In addition all spaces have proper
communicators now.

Paragraph 12.8/15 of the C++11 Standard:

The implicitly-defined copy/move constructor for a non-union class X
performs a memberwise copy/move of its bases and members

* ContinuousLagrangeSpaceBase -> Spaces::ContinuousLagrangeBase
* ContinuousLagrangeSpace::FemWrapper
  -> Spaces::ContinuousLagrange::FemBased
* ContinuousLagrangeSpace::FemLocalfunctionsWrapper
  -> Spaces::ContinuousLagrange::FemLocalfunctionsBased
* ContinuousLagrangeSpace::PdelabWrapper
  -> Spaces::ContinuousLagrange::PdelabBased
* DiscontinuousLagrangeSpace::FemLocalfunctionsWrapper
  -> Spaces::DiscontinuousLagrange::FemLocalfunctionsBased
* RaviartThomasSpace::FemLocalfunctionsWrapper
  -> Spaces::RaviartThomas::FemLocalfunctionsBased
* FiniteVolumeSpace::Default
  -> Spaces::FiniteVolume::Default

* this can be used with space.tools to automatically create an appropriate
  grid view or part, as needed for each space