Changes between 5.9.0 and 5.10.0.RC2

This is a pre-release for 5.10.0, a maintenance release with a usability improvement, bug fixes, and dependency upgrades. All users of the 5.x.x series are encouraged to test this version.

Add TLS settings for property-based configuration

GitHub issue: #646

Remove unnecessary lock acquisition

GitHub issue: #650

Channel state not cleaned when using abort

GitHub issue: #661

Bump optional dependencies

GitHub issue: #660