Encoding methods used:
- Tag localities: Run length encoding
- Tag ids: Compact representation
- Commit versions: delta encoding.
If "n" is the number of entries in the version vector, with the tags
spread over "m" data centers, these techniques will reduce the number
of bytes to represent the version vector from "(11 * n)" bytes to
"(3 * m + 2 * n)" / "(3 * m + 3 * n)" bytes (depending on the max tag
id value, and ignoring some constants) in the best case.
sfc-gh-tclinkenbeard