MKVToolNix (64-bit)

What's new in this version:

New features and enhancements:
- mkvmerge: the options `--default-track` and `--forced-track` have been renamed to `--default-track-flag` and `--forced-display-flag` respectivelyfor improved consistency with other option names & the wording used in the GUI. However, the old names will be supported and recognized indefinitely. What will remain unchanged is the property names for those flags in mkvmerge's identification output. Existing third-party programs will continue working as they are.
- mkvmerge: added a new option `--track-enabled-flag` to set or unset the "track enabled" track header flag
- mkvmerge: MP4 reader: `mkvmerge` will now evaluate the `flags` field of the track header atom (`tkhd`) and set the track's "enabled" flagaccordingly. Implements #3272.
- MKVToolNix GUI: multiplexer: added support for the "track enabled" track header flag.
- MKVToolNix GUI: multiplexer, header editor: added several menu entries & keyboard shortcuts for toggling various track flags of the currently selected tracks, e.g. `Ctrl+Alt+F, D` (that's `Ctrl` and `Alt` with `F` simultaneously followed by `D` without any other key pressed) for toggling the "default track" flag. Part of the implementation of #3253.
- MKVToolNix GUI: multiplexer, header editor: added menu entries & keyboard shortcuts for setting the language of the currently selected tracks to one from a configurable list of languages. The shortcuts used are `Ctrl+Alt+A, 1` through `Ctrl+Alt+A, 0` for the first ten entries of that list (that's`Ctrl` and `Alt` with `A` simultaneously followed by a digit without anyother key pressed). Part of the implementation of #3253.
- MKVToolNix GUI: chapter editor: if the user enters commas in start or endtimestamps they will automatically be changed to points as the decimal separator, allowing for easier copy & paste from other programs/sources. Implements #3273.
- MKVToolNix: header editor: the selected track or attached file can now be moved up & down with the keyboard shortcuts `Ctrl+Up` & `Ctrl+Down` respectively. Part of the implementation of #3253.

Fixed:
mkvmerge: Matroska reader: DVB subtitle tracks with a codec private data size of more than five bytes are accepted now, too