Release 2021.1

• License change: changed license of open source version to GPLv3
• upgraded POCO to release 1.11.0
• upgraded OSP and RemotingNG frameworks (see respective release notes)
• MQTT: support for MQTT version 5, upgrade bundled Paho library
• JavaScript: new UUID object
• JavaScript: fixed potential heap corruption with asynchronous HTTP requests
• JavaScript: fixed potential double free in BridgeWrapper
• JavaScript: HTTP request and response object have new headers property
• JavaScript: fix a race condition when stopping a script
• JavaScript: add toJSON() to Buffer, DateTime, LocalDateTime and UUID objects
• Upgrade OpenLayers to newer version to fix Safari display issues