[Buildsystem] Tell build systems to remove VTK output files
[stokesdarcy2] Switch to new, unified PkFEM
[stokesdarcy2] Switch from hard-to-obtain ADRWIP operator to standard ConvectionDiffusionDG
[stokesdarcy2] Port VTK output functions to new infrastructure
[VTK] Add an initial version of a VTK function base class
Add new Poisson example with Dirichlet-Neumann iteration
Some cleanup in dirichlet-neumann example

Most importantly, the actual problem setup (after grid creation and
space definition) is now moved to a separate function.
[SubDomainSet] Add second constructor that takes an initializer list

That's a whole lot easier than the weird variable template argument
trick, and since we can now rely on compilers supporting this feature,
let's profit from it.
[Tests] Clean up Dirichlet-Neumann example
[Tests] Add new test for measuring assembly performance
[VTK] Improve support for custom VTK output
[stokesdarcy2] Use new, improved VTK output support
[stokesdarcy2] Formattingc
[stokesdarcy2] Some changes to the problem
[CouplingGFS] Make compatible with new, hierarchy-aware function spaces in PDELab
Diverse bug fixes
[Release] Bump version to 2.0.0
[Buildsystem] Fix typo in Makefile.am
[Version] Bump to 2.0.1

Fix a stupid typo that prevented the autotools from working.
Merge branch 'releases/2.0'

Pull in mountain of fixes from 2.0 release

* releases/2.0:
  [Version] Bump to 2.0.1
  [Buildsystem] Fix typo in Makefile.am
  [Release] Bump version to 2.0.0
  Diverse bug fixes
  [CouplingGFS] Make compatible with new, hierarchy-aware function spaces in PDELab
  [stokesdarcy2] Some changes to the problem
  [stokesdarcy2] Formattingc
  [stokesdarcy2] Use new, improved VTK output support
  [VTK] Improve support for custom VTK output
  [Tests] Add new test for measuring assembly performance
  [Tests] Clean up Dirichlet-Neumann example
  [SubDomainSet] Add second constructor that takes an initializer list
  Some cleanup in dirichlet-neumann example
  Add new Poisson example with Dirichlet-Neumann iteration
  [VTK] Add an initial version of a VTK function base class
  [stokesdarcy2] Port VTK output functions to new infrastructure
  [stokesdarcy2] Switch from hard-to-obtain ADRWIP operator to standard ConvectionDiffusionDG
  [stokesdarcy2] Switch to new, unified PkFEM
  [Buildsystem] Tell build systems to remove VTK output files