Michael Zingale

this seems to work well for the HSE boundary, but it does not see to work with the -x boundary in axisymmetric coords. This might be because we need to...

as an example, Sedov 2-d in axisymmetry crashes after a while.

The way to do this to match what we do with PLM (which uses the Saltzman 1994 approach) is to only use the one-sided stencil for velocity. Then also reflect...

this has been updated to work with pslope

essentially we'd need to do this in `main.cpp` before the `amrptr->init(strt_time,stop_time);`. We'd need to rebuild the ref_ratio array here to compute the finest level number of zones.

It seems the best way to do this is to remove any problem initialization stuff from `probinit` and create a new Castro-owned initialization routine that call with this info that...

I think most of what was needed for this is now done.

I think the way to this is to just fill ghost cells on the level for the derive MF, convert to centers, do the derivation including 1 ghost cell, and...

So in order to implement this, we need a mask.

closes #1603