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
metablock variation on https://github.com/rackerlabs/deuce-valere/pull/12/files#r21829046