Filestore cleanup is too slow

[TheDiscordian]

Maybe we can speed it up by only removing offset 0 references, see if that fixes filestore errors just as well, and we can let the gc clean up the rest later.

[TheDiscordian]

We can't remove just offset 0, we must remove all the blocks, but we can just check offset 0, before we build the list to remove (1 bad block, then they're all bad blocks EDIT: This is incorrect, some blocks might be shared by other objects).

[TheDiscordian]

filestore/verify can be asked to verify just a specific object. This will hopefully dump us back the blocks that are truly unfindable, and then we can safely remove those :D.

[TheDiscordian]

Unfortunately it doesn't take an object, but actually a block, this is a shame. We can use refs to get all the CIDs, can't omit the irrelevant ones, but that's fine for now.

[RomeSilvanus]

Please haste, codefriend

[TheDiscordian]

Fixed in 78d6721