V1.2.1

• Deduplication was remade so it doesn't require writing to iterate over table content twice
  This increases writing performance by ~20% when deduplication is enabled
  Size of buffer is a little smaller since a separate table containing the deduplicated values is no longer needed

• Writing in general is faster, especially if there's many subtables

• Added allowdeduplication parameter to encoder.read(), This should be enabled if the buffer had deduplication enabled when writing.