Release 2.1

A small update release introducing a few additional capabilities

• Add functions for changing color gain (saturation) and brightness (#8). The color gain can be increased on the fly using assignable shortcut keys, or can be set to a fixed value as scene action.
• Add API commands to libvisca for reset/set/get Color Gain (Saturation) and set/get Brightness.
• Make previously hardcoded pan, tilt, zoom and focus speeds configurable per camera, add shortcuts for live modification (#6)
• Add compatibility for cameras that implement a deviating Visca standard. Sequence numbering is not applied for NewTek PTZ1 NDI camera since that camera does not properly handle message counters.
• Bugfix in queue handling of when ack has not been received yet and multiple items are queued.
• Add unit tests to the repository and configure automating workflows to run unit tests
• Bugfix to repair behavior of backup button and related path controls in the settings dialog that cause a crash on certain OBS builds

In addition, a code cleanup and and class restructuring was applied without functional impact (thanks @CapsAdmin).

Full Changelog: 2.0...2.1