[Dune] website git errors

[Christian Engwer]

> > a) doxygen
> >   I think we should first switch to a setup which includes linking to
> >   other doxygen instances as this will dramatically increase the
> >   usability, but might require some radical changes.
> 
> What exactly do you mean by that? The ability to include other documentation sets (e.g. dune-fem)?
> That should already work (it is controlled by adding metadata to the frontmatter of a release or
> a module). The doxygen documentation is then built in a nightly cron job.

When building doxygen you can refer to the doxygen documentation of
source code you depend on. In this sense I think we should only have
per-module documentation, except for a modules page and include the
other modules only as "dependencies".

See
http://www.stack.nl/~dimitri/doxygen/manual/external.html

I never did this myself, but it would avoid issues like we have them
now:

(A) per module documentation lacks certina information: e.g. dune-grid
    does not include/link to Dune::FieldVector
(B) modules like dune-pdelab include all other modules in the
    documentation to avoid (A), but this clutters the module page and
    you loose the over-view which module contains which classes

Christian