Session::mount will now return a Future that completes when the mount
does, whose result is another Future that completes when the file system
is unmounted. This allows consumers to know whether the mount succeeded
without waiting for a future unmount.
Session::mount will now return a Future that completes when the mount does, whose result is another Future that completes when the file system is unmounted. This allows consumers to know whether the mount succeeded without waiting for a future unmount.
Fixes #27