Local hyper-cache management

[pfrazee]

Need tooling to delete hypers from your local cache, see #20

[trafgals]

Would also be great if a user could:

1. Remap the location of the .hyperdrive folder (For me on Windows I would like to move it off my C: drive, where space is limited and I can't control redundancy)
2. Access files in .hyperdrive using the native filesystem, avoiding the need to store double total storage use when sharing (one for the 'original' version, and one for the hyperdrive cache copy)