autochunk: option to save all simulated data to disk

[caglorithm]

WIP, maybe netcdf?

[jajcayn]

yes, that would be doable.. xarray supports saving to netcdf with a option, which is append. AFAIK, each chunk would be saved with correct time dimension with a option, and this would result in one big nc file with stitched chunks

[caglorithm]

Another option would be storing into HDF files btw. Will also consider it, but xarray is nice because its structured and probably more flexible.

I guess I'll get my hands dirty with xarray & netcdf then and ask for your help :)