remove genericgeometry subdirectory from dune-geometry

The removal of the genericgeometry subdirectory in dune-geometry will require some minor changes to dune-grid. This merge request collects those and should be merged once the corresponding branch in dune-geometry is merged, too.

Changed title: [WIP] use Impl::FieldMatrixHelper instead of GenericGeometry::MatrixHelper → [WIP] remove genericgeometry subdirectory from dune-geometry

Milestone changed to %DUNE 2.5.0

Added 3 commits:

• 03366f7e...fbcb1974 - 2 commits from branch master
• d6516c57 - use Impl::FieldMatrixHelper instead of GenericGeometry::MatrixHelper

Added 1 commit:

• 7ea5b223 - use SimplexTopology, CubeTopology from namespace Impl

Unmarked this merge request as a Work In Progress

Enabled an automatic merge when the build for 7ea5b223 succeeds

Added 1 commit:

• fa5ac136 - add missing include

@christi, can you merge this when the build succeeds?

Unfortunately, the previous build failed due to a missing include.

Enabled an automatic merge when the build for fa5ac136 succeeds

Mentioned in commit aafbf29e

Status changed to merged

Mentioned in commit 60948833

Mentioned in merge request !132 (merged)

Mentioned in issue dune-geometry#4 (closed)

Mentioned in commit 63340ecb