[Dune] Dune 2.6.0rc2 Released

[Markus Blatt]

For those (like me) not following github regurlarly and not have
dune-project.org as startup page. I am sorry to bother everyone else
with 2 week old news, but I only found out because of test reported
to the dune-devel list this week. Chances are that I am not the only one.

Here is the official old news:

The second release candidate for the upcoming 2.6 release is now
available. You can download the tarballs [1], checkout the v2.6.0rc2
tag via Git - there is no prebuilt packages from Debian experimental
yet. Please go and test, and report any problems that you encounter.

Included in the release candidate are the core modules [2]
(dune-common, dune-geometry, dune-grid, dune-istl,
dune-localfunctions). Release candidates for dune-alugrid and
dune-python are also included. 

Please refer to the recent changes [3] page for an overview of what
has changed in the new release - please let us know if something is
missing from there.

[1] https://dune-project.org/releases/2.6.0rc2
[2] https://gitlab.dune-project.org/core/
[3] https://dune-project.org/dev/recent-changes