feat(splitter): chunking projectid, vaultid, start_marker and end_marker

This patch allows every vaultid specific to a projectid to be chunked
with a start marker and end marker. This allows the manager to be
instantiated with a different start and end marker when calling the
validation functions.

Addresses Issue: https://github.com/rackerlabs/deuce-valere/issues/10
L64-L83 - Why not simply do:

```
if not len(self.vault.storageblocks):
    return ([[self.vault.project_id,
                   self.vault.vault_id,
                   None,
                   None]])
```
?
Then allow the loop to fill everything out. L71-L72 doesn't seem like it isn't doing anything that the loop could not do for you.