[parallelgrid][cleanup] Remove unused header include

See merge request !10

Feature/test parallel grid in parallel

See merge request !8

[paralellgrid] Implement intersection iterator that skips ghost-ghost and ghost-boundary intersections

Fix dune-parallel grid with dune master

See merge request !5

Cleanup/cmakelists

See merge request !6

[gitignore] Add some useful things to gitignore

See merge request !7

[parallelgrid] Overload hierarchic iterator interface for codim-0-entity to fix iterator constructor

and make test compile.

Some updates for parallelgrid

See merge request !2