Perform only spatial prolongation when using a single timelevel and tag 'prolongation="copy"'

[Miguel Zilhão]

Sometimes it is useful to set a grid function that does not evolve at all. However, using a single timelevel and tag 'prolongation="copy"' results in a Carpet assertion failure.

This is fixed in the following commit d13a6e245a3d7d2b575094fd0def540d510a166c, as discussed in the following thread: http://lists.einsteintoolkit.org/pipermail/users/2017-October/005835.html

Could this be merged to master?

Keyword:

[Erik Schnetter]

We can introduce a new prolongation operator and/or introduce a way to set the desired time prolongation order per grid function group.