Bug#1082567: deal.ii: new upstream release needed to support sundials 7

[Drew Parsons]

Source: deal.ii
Version: 9.5.1-3
Severity: important

sundials 7 (in experimental) introduced enough API changes that
probably break deal.ii 9.5.  deal.ii 9.6 has already been updated to
support sundials 7, so please update to the latest upstream release.

Note that sundials 7 moves MPI support into the core library, due to
sunmpicomm introduced in https://github.com/LLNL/sundials/pull/370
So a standard deal.ii build might fail with 
"sundials_types.h:57:10: fatal error: mpi.h: No such file or directory"

If this is the case for deal.ii and it's not already managing it's own
MPI include directories, then the issue can be worked around by
configuring the C++ compiler to mpicxx for the deal.ii build.


We want to upload sundials 7 soon (transition #1082552), at which
point this bug would likely become severity: serious