This patch makes most constructors and all observers of GeometryType
constexpr, basically everything that can be mode constexpr within the
limits of C++11 (GCC 4.9 does not support generalized constexpr).

Improve GeometryType documentation

See merge request !53

Put constructors and comparison operators in their own doxygen member
groups.

.gitlab-ci.yml: update environments

See merge request !50

 - Added:   Debian 10 with gcc in C++17 mode
 - Removed: Debian 8 + Backports with clang

Reference: http://lists.dune-project.org/pipermail/dune-devel/2017-July/002224.html

Use the explicit constructor to construct quadrature data from strings

See merge request !49

This is needed for Steffens opcounting.

Only whitespace changes, but this makes sure those whitespace changes are not
part of future diffs.

Rationale: gcc-4.9 coughs up on the specialization of Hybrid::forEach for
std::integer_sequence when fed with the result of Std::make_integer_sequence.
As we require a C++14-compatible compiler (at least to the extent of gcc-4.9),
this patch resolves the issue by using std::make_integer_sequence instead.

[Fix] Update mailing lists addresses.

See merge request !48

Change module version number to 2.6-git

See merge request !46

[cleanup] fix inconsistencies after renaming functions in !35

`geometryTypeFromVertexCount()` was named `geometryTypeFromVertices()`
in earlier versions of merge request !35 and the old name was still used in some places.

See merge request !43

geometryTypeFromVertexCount() was named geometryTypeFromVertices()
during developement and the old name was still used in some places.

Correct two minor errors introduced in !35

See merge request !42

Just in case it gets no longer included indirectly due to future
changes.

Feature/fromvertices

see issue #1 

we move the makeFromVertices implementation into a utility function, which clearly states that it only works up to 3D.

See merge request !35

Do not install `jacobian.mac`

The file is not a header, but a generator for quadrature rules. It is
only useful when building dune-geometry.

See merge request !39

Ansgar Burchardt authored 8 years ago and Christoph Grüninger committed 8 years ago

The file is not a header, but a generator for quadrature rules. It is
only useful when building dune-geometry.

Build `test-nonetype`

See merge request !33

[cleanup] use delegating constructors for AffineGeometry

Since we started to require C++11-compatible compilers, we can now make
use of delegating constructors to remove code duplication and make the
intention of the constructors more clear.

AffineGeometry's constructors always come in pairs: one taking a
ReferenceElement and one taking a GeometryType. Since the GeometryType
is only used to look up a ReferenceElement and then proceed identical to
the former constructor, we can instead delegate the actual construction
from the latter to the former constructor.

See merge request !36

Use Hybrid::forEach instead of wrapper ForLoop

Use `Hybrid::forEach` instead of wrapper `ForLoop`.

See merge request !37

Since we started to require C++11-compatible compilers, we can now make
use of delegating constructors to remove code duplication and make the
intention of the constructors more clear.

AffineGeometry's constructors always come in pairs: one taking a
ReferenceElement and one taking a GeometryType. Since the GeometryType
is only used to look up a ReferenceElement and then proceed identical to
the former constructor, we can instead delegate the actual construction
from the latter to the former constructor.