[selectiontest] Clean up includes.

See merge request core/dune-common!373

This replaces `remoteindices.hh` with `plocalindices.hh`; as a result this
test can now be compiled without MPI.

Thanks to @felix.gruber for the initial report (see !372).

Deal with dune/common/array.hh

Closes #13

See merge request core/dune-common!359

[bugfix] make `dune_add_test` play nicely with MPICH

Closes #24

See merge request core/dune-common!363

Thanks to @smuething for the hint.

Note: This patch changes the semantics of the command. Up to now, the command
      was allowed to contain arguments (unless it was a target). With this patch,
      the arguments must be passed separately.

[cmake] Fix vverb not recognized as MINIMAL_DEBUG_LEVEL

See merge request core/dune-common!356

This deprecates the header `<dune/common/array.hh>` and all of its members.
- `Dune::array`: use `std::array` instead.
- `Dune::make_array()`: use `Dune::Std::make_array()` instead.
- `Dune::fill_array()`: use `Dune::filledArray()` instead.

Note that deprecation warnings for `array` and `make_array` could not be
implemented, since those were implemented by using declarations and it seems
to be impossible to deprecate those.  Users should still get a note though
since the entire header is deprecated.

For `fill_array()` there was no replacement, so this commit introduces
`filledArray()` with a slightly improved calling syntax, a better name, and
(in C++17) support for `constexpr` arrays.  To make it possible to deprecate
`array.hh`, that replacement is in its own header `filledarray.hh`.

This commit also introduces two unit tests:
- `filledarraytest.cc` to test `filledArray()`, and
- `arraydeprecationtest.cc` to make sure the deprecation syntax is supported
  for all tested compilers.  (It also has a feature to check that deprecation
  warnings are really displayed, but that is disabled for regular unit testing
  since the logs have to be checked manually for the warnings.)

[bugfix] fix version detection in `dune_python_find_package`

Closes #75

See merge request core/dune-common!364

There were two bugs:
- The variable `PYPACKAGE_RESULT` was set instead of `${PYPACKAGE_RESULT}`.
- The output script `pyversion.py` was silently ignored, yielding an
empty version string.

This fixes #75.

The standard `add_test` allows CMake targets to be passed as commands.
However, when passing them to MPI, this does not work in two cases:
- MPICH does not search for the executable in the current working
directory.
- The name of the executable need not coincide with the name of the
target (e.g., on Windows).

This patch fixes both issues by checking whether the command is a CMake
target and obtaining the location of the primary output file in this
case. This name is then passed to MPI or `add_test`, respectively.

This closes #24.

[debugalign.hh] Fix indentation.

See merge request core/dune-common!362

[fmatrixtest] Fix an annoying set-but-unused-variable warning.

See merge request core/dune-common!357

[dunecontrol] evaluate CMAKE_MODULE_PATH from opts file

Closes #25

See merge request core/dune-common!355

up to now a CMAKE_MODULE_PATH environment variable was properly considered
and appended to the cmake parameters. This did not work for an environment
variable specified in the opts file. This patch makes the behaviour
consistent between shell environment and opts file variables.

(fixes #25)

[bugfix] correct DUNE_VERSION_NEWER alias

See merge request core/dune-common!353

The semantics of the old macro DUNE_VERSION_NEWER is DUNE_VERSION_GTE,
not the opposite. While we're at it, also fix the deprecation message to
suggest DUNE_VERSION_GTE instead of DUNE_VERSION_GE.

[bugfix] Fix compile error with NDEBUG

See merge request core/dune-common!352

It seems that the `#if ...` was originally introduced to avoid
a compiler warning in case later `assert()` are removed due to
NDEBUG. When changing to `TestSuite` in e7b592a2 this
was not adjusted.

**Surprisingly no one compiled our tests with NDEBUG since June 2017 otherwise this would have triggered a compile error!**

Replace DUNE_VERSION_NEWER with DUNE_VERSION_GTE.

See merge request core/dune-common!329

[bugfix] silence signed/unsigned comparison warning

See merge request core/dune-common!349

cmake: fix regex for hidden files

See merge request core/dune-common!330

[Vc] Deal with the missing swap() on Vc proxies.

Closes #59

See merge request core/dune-common!339

This is needed to pull in the fix for #88.

[Vc] Work around missing std::for_each_n() in g++ 7.2.

Closes #88

See merge request core/dune-common!341

`Vc/common/algorithm.hh` uses `std::for_each_n()` when it detects C++17, but
g++ 7.2 does not seem to provide it (yet).  Work around this by disabling the
macro that signals C++17-support in Vc.

Closes: #88.

This is a problem with Vc 1.3.0.  Vc 1.3.2 seems to have implemented
`swap()`.

We work around it using copying and a temporary to implement `swap()` on our
own wrapping proxies.  Any member type of a Vc SIMD type should be a
fundamental type, so we don't bother using moves.

Closes: #59.

Deal with Vc access proxies

Closes #59

See merge request core/dune-common!338

This is needed by the `luDecomposition()` in densematrix.hh

This is needed because newer versions of Vc introduce their own proxies as the
result of expression like `v[0]`.  These proxies cannot be constructed outside
of Vc, not even by copying or moving, so we cannot pass them out of our
`lane()` function.  We work around this by introducing our own proxy class,
that we can copy.

That proxy class was originally introduced for !193 (Proper SIMD Interface)
and has been backported for the 2.6 Dune release.

Closes: #59

bump version to 2.7-git [ci skip]

See merge request core/dune-common!337

parallel index sets: correct typo; return value of AllSet::contains() [ci skip]

See merge request core/dune-common!335