Merge remote-tracking branch 'remotes/origin/v4.x'

src/main/java/uk/yermak/audiobookconverter/ArtWorkImage.java

src/main/java/uk/yermak/audiobookconverter/Conversion.java

.../java/uk/yermak/audiobookconverter/ConversionContext.java

...main/java/uk/yermak/audiobookconverter/FFMediaLoader.java

...in/java/uk/yermak/audiobookconverter/Mp4v2ArtBuilder.java

src/main/java/uk/yermak/audiobookconverter/StreamCopier.java

src/main/java/uk/yermak/audiobookconverter/Utils.java

src/main/java/uk/yermak/audiobookconverter/Version.java

...va/uk/yermak/audiobookconverter/fx/ArtWorkController.java

...java/uk/yermak/audiobookconverter/fx/ArtWorkListCell.java

...uk/yermak/audiobookconverter/fx/ConverterApplication.java

...ava/uk/yermak/audiobookconverter/fx/TuningController.java

...n/resources/uk/yermak/audiobookconverter/fx/art_work.fxml

...ain/resources/uk/yermak/audiobookconverter/fx/output.fxml

...ain/resources/uk/yermak/audiobookconverter/fx/tuning.fxml