Release 1.2.3 - 20.06.2020

NEW FEATURES
- Livestream: added new module for RTP live-streaming (H.264 encoded),
  allows to stream live video from frames with some delay (issue #288).
- Testing/CI: improved internal testing capabilities and Continuous
  Integration infrastructure (issue #309).

BUG FIXES
- SDK API EventStore: add slice(size_t) to be more consistent with other
  parts of the API (issue #333).
- File Input: discard data if a decompression error happens (issue #334).
- File Input: fix reading files with custom types in them (issue #280).
- Undistort: fix startup failure if only a frame input was connected
  (issue #332).
- Ubuntu packages: do not auto-enable systemd service (issue #329).
- System Service: block shutdown of runtime from clients if the runtime
  was started as a system service (issue #313).
- Core: show username the runtime is running under in ConfigTree, available
  at /system/ 'user' string (issue #306).