• Fix #164
• #130 supports upsert
• Enable mt_static on Windows

Add more operations for aggregations: https://www.polodb.org/docs/advanced/aggregation

• $addFields
• $unset
• $skip
• $limit
• $group
• $sort
• more friendly errors

This is a major change:

• Change license to Apache-2.0
• Add standalone server that supports MongoDB's wire protocol

Breaking changes:

• RocksDB as storage layer
  • Make the DB more stable and performant in storage. You don't need to worry about data lose any more.
  • PoloDB is no longer a single file DB.
• Remove WASM support
  • Maybe we can add back in the future, but we must remove it now
• Remove memory db
  • Maybe we can add back in the future, but we must remove it now
• Simplify API
  • Transaction API
  • Unify ClientCursor and ClientSessionCursor