0.9.0: Replicaset support

• Implemented #9: Reconnect - according to specification, by checking
  a connection with the ping command if it has been not used for a
  defined number of seconds (defaulting to 5)
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• Merged PR #10: Sessions. Adds support for passing sessions to all of
  the database and collection methods.
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• Merged PR #5: Add support for mongodb+srv. This adds support for DNS
  seed lists, as well as reading from and writing to separate connections
  based on the read preference supplied.
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0.8.0: Protocol error handling

• Changed implementation to raise peer.ProtocolException instead of
  low-level socket errors
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0.7.2: SASL authentication fixes

• Fixed #6: Exception com.mongodb.Error (#40415:Location40415 "BSON field
  'saslContinue.done' is an unknown field.")
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• Fixed #7: Array to string conversion error in Document::toString()
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0.7.1: XP11 compatibility

• Made library compatible with XP 11 - @thekid

0.7.0: SSL / TLS support, PHP 8.1 fixes

• Fixed PHP 8.1 compatibility for IteratorAggregate / ArrayAccess return
  type declarations
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• Fixed issue #4: Cannot handle binary subtype 3 - @thekid
• Enable SSL/TLS if ssl=true or tls=true is passed in the connection
  string parameters; implements feature request #2
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• Made params for Collection::command() optional - @thekid

0.6.0: Simplified API

• Added Cursor::first() to return the first document (or NULL).
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• Made Collection::find() also accept IDs to find single documents
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• Added Collection::command() to run arbitrary commands - @thekid
• Simplified usage of collection methods update() and delete()
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0.5.3: Socket reading fix

• Fixed reading to ensure we have enough bytes when reading packets
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0.5.2: NULL fix

• Fixed error #22 (InvalidBSON) when using NULL values - @thekid

0.5.1: Aggregation fixes for transactions

• Rewrote count() and distinct() to use aggregation pipelines. See
  https://docs.mongodb.com/manual/core/transactions/#count-operation and
  https://docs.mongodb.com/manual/core/transactions/#distinct-operation
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0.5.0: Aggregation

• Added new methods Collection::distinct() and Collection::count()
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• Added new method Collection::aggregate() to perform aggregations, see
  https://docs.mongodb.com/manual/reference/command/aggregate/ and
  https://docs.mongodb.com/manual/reference/operator/aggregation/lookup/
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• Fixed all places where _id was assumed to always hold ObjectIds.
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