'download-cache' setting support?

[danielsokolowski]

Is it possible/does it make sense for mr.developer to honor the download-cache build out setting? Similar to http://pypi.python.org/pypi/zerokspot.recipe.git/.

My thinking this would allow one to have a local cache of packages that can be distributed with the project for the odd chance when the source goes down or becomes unavailable for some other reason; small chance but has happened to me.