This makes the new typed serialization the default (the old
serialization is not used but the code has not been cleaned up yet).
Some things are no working in the new world:
Chunking - The compound list is not working correctly any more. The
Chunks method is having issues because it assumed things based on the
old implicit chunking.
Commit - uses a `Set(Commit)` which means that the parent commit is
embedded. We need to change that to be `Set(Ref(Commit))` so that the
parent commit is referenced instead.
this point the compoundBlob only contains blob leafs but a future
change will create multiple tiers. Both these implement the new Blob
interface.
The splitting is done by using a rolling hash over the last 64 bytes,
when that hash ends with 13 consecutive ones we split the data.
Issue #17
This will enable us to walk the chunk graph without having to go
through weird contortions to figure out which values don't have
chunks in any chunkstore (because they were inlined).
Towards issue #82
