AMR tests

Should look as on ​this page.

Obviously not working quite right - could be recombination problems, but seems likely that at least part of the problem is communication between patches. Perhaps related: can only use up to 64 cores. After that, crashes after advancing at most to second level of grids.

Would like to merge line_transfer and HotJupiter branches.

Heating rate

rates(i,j,k,iioniz)=f*(1d0-emtau)/dx               !has computational units of number per volume per second
rates(i,j,k,iheat)=f*(1d0-emtau)/dx*egamma_scale  !has computational units of energy per volume per second

Heating rate → de/dt

\frac{(1-e^{-\tau})}{dx} \stackrel{?}{=} e^{-\tau}\sigma n_H