Enhancement api integration

Integrate the use of Vault, File/Files, Block/Blocks into the rest of the Deuce-Client.

DEPEND: PR #12
Because we don't know what the client wants to do with the data represented by the Block object.

This call deletes it from the Deuce Server and allows the caller to determine what to do with the actual Block.

I did think about removing it, but then decided the caller should be responsible for doing so, at least for now.

Also note that we do not enforce that the Block is part of the vault.blocks list.