* arts-2-1-510

* CMakeLists.txt:

Account for bugfix in cmake 2.8.10 [1]. They now enable NDEBUG also in
RelWithDebInfo configuration which turns off assertions. We don't want
that.

[1] http://public.kitware.com/Bug/view.php?id=11366

git-svn-id: https://www.sat.ltu.se/svn/rt/arts/trunk@8218 aaf1aab0-4228-0410-ad68-8dceda47f409