[Users] Serious problem with Carpet grids

Hi,

I just created a ticket (https://trac.einsteintoolkit.org/ticket/1846) to describe a problem that Barry Wardell and I found with the current (2015_11) release. It has probably been present for a while, but is not present in the 2014_05 release. This would show up as large grids and memory usage, and low speeds, in simulations with multiple components per refinement level, as Carpet seems to be replacing these components with their containing bbox. There are two simple workarounds described in the ticket.