* mkvextract: chapters, tags & cue sheets will now be written to standard
output if no file name is given, same as if `-` is given as the file name.
* MKVToolNix GUI: job queue: added a new setting in the preferences’ “job
queue & job status” section that, when enabled, will cause the GUI to remove
all output files created by jobs that are either aborted by the user or that
end in an error. Implements #2614.