[Tech Preview] Hashstore backend for storage nodes

[Alexey]

You need also enable these features as well:

@littleskunk

# Enable passive migration. (requires version v1.119)
# WriteToNew will send all incoming uploads to the new hashstore backend
# TTLToNew will send only uploads with a TTL to the new hashstore backend
# ReadNewFirst will migrate any piece that gets hit by a download request
# Not sure what PassiveMigrate does. By the time you think about this one you most likely have them all set to true anyway.
echo '{"PassiveMigrate":false,"WriteToNew":false,"ReadNewFirst":false,"TTLToNew":false}' > 121RTSDpyNZVcEU84Ticf2L1ntiuUimbWgfATz21tuvgk3vzoA6.migrate
echo '{"PassiveMigrate":false,"WriteToNew":false,"ReadNewFirst":false,"TTLToNew":false}' > 12EayRS2V1kEsWESU9QMRseFhdxYxKicsiFmxrsLZHeLUtdps3S.migrate
echo '{"PassiveMigrate":false,"WriteToNew":false,"ReadNewFirst":false,"TTLToNew":false}' > 12L9ZFwhzVpuEKMUNUqkaTLGzwY9G24tbiigLiXpmZWKwmcNDDs.migrate
echo '{"PassiveMigrate":false,"WriteToNew":false,"ReadNewFirst":false,"TTLToNew":false}' > 1wFTAgs9DP5RSnCqKV1eLf6N9wtk4EAtmN5DpSxcs8EjT69tGE.migrate