Enhancement api integration

Integrate the use of Vault, File/Files, Block/Blocks into the rest of the Deuce-Client.

DEPEND: PR #12
No, just block ids - [blockids]. This is now validated by stoplight.

Offset is looked up from vault.files[file_id].offsets. There is also a lot of validation not enforceable by stoplight to ensure that the blocks are there in vault.files.blocks and vault.files.offsets.