Dynamically adding/removing blockstores from an experiment
Make swapmod work for adding or removing remote blockstores. Maybe not so useful for local blockstores.
Use case: you have accumulated a lot of local disk state in an experiment and decide you would like to continue work in the future. It would be nice if you could just map in a blockstore, copy all the data into it, and then swapout your experiment.
Broken out from issue #193 (closed).