Buiter 2016 benchmark currently crashes mid-run

[naliboff]

As reported in this forum post, the high resolution 2016 Buiter thrust wedge benchmark currently crashes during the model run.

This is likely due to a combination of changes over the years, and the likely fixes are:

1. Use AMG instead of GMG (originally run with AMG)
2. Reduce the CFL number
3. Switch from DG fields to particles