Before this commit communcation would be initiated even on empty
interfaces. While this does not lead to overwriting data or producing
segmentation faults, it does lead to accessing the first component of
empty vectors to get a pointer to pass to MPI functions. This produces
error output with valgrind and other memory debuggers. Therefore with this
commit we will first check whether the interface contains values and do
nothing if it doesn't. We also augmented the test to catch the case wher only
some processes have an empty interface.

Like we do for Autotools.
This is only supported for CMake 3.0 or newer. Oder versions ignore
the property and report the test as failed.

"Makefile.in", "*.o", etc. need only be listed in the toplevel .gitignore, the
rules are applied recursively.

Test programs etc. should be listed as "/program" in their directory's
.gitignore, so they are not accidentially ignored in a lower level directory.

These headers were moved in Dune 2.3.

This patch introduces a new macro DUNE_UNUSED_PARAMETER(parm) for marking
unused parameters that are there for a purpose (e.g. the prescribed interfac
The macro simply performs a cast to void. In addition all unused parameter w
that I found were removed.

With this patch VariableSizeCommunicator now really supports a varying number of data entries
per index during communication.

[parallel,release] Adds a new buffered communicator that does not need to know the data amount per index when receiving.

During communication of data with a parallel DUNE grid the amount of data items
received at an index is not known at the receiving side. With this communicator
it is possible to build such a communication based on index lists at the sending
and receiving side. With this patch only fixed size of data items per index is
supported.

[[Imported from SVN: r7124]]

[[Imported from SVN: r6926]]

[[Imported from SVN: r6925]]

[[Imported from SVN: r6886]]

It is not standard conforming.

This file must have missed when deleting th backwards compatible code.

[[Imported from SVN: r6681]]

Now make test works in all directories.

[[Imported from SVN: r6679]]

[[Imported from SVN: r6662]]

the ENABLE trick).
Added an utility cmake function to add the necessary flags for
compilation and linking.

[[Imported from SVN: r6614]]

[[Imported from SVN: r6611]]

  directories. This seems to be more manageable.
- Deactivated building of the test during make all. Seems annoying to
  our users.
- Introduced make check mimicing autotools.

Tests still fail where they should not.

[[Imported from SVN: r6610]]

Temporarilly remove syncertest from building.
Add some comments to config.h.cmake.

[[Imported from SVN: r6591]]

Exclude linking to MPI_CXX_LIBRARIES if MPI not found.

[[Imported from SVN: r6590]]

Added support for MPI.
Write module version information to config.h.

[[Imported from SVN: r6588]]

directory.
[CMake] make builds more than half of the tests.

[[Imported from SVN: r6580]]

Only ctest is working.

[[Imported from SVN: r6577]]

[[Imported from SVN: r6424]]

* if a test doesn't test anything, return 77 to skip this test

[[Imported from SVN: r6419]]

This makes the test compile again.

[[Imported from SVN: r6276]]

[[Imported from SVN: r6275]]

[[Imported from SVN: r6266]]

[[Imported from SVN: r6265]]