community/mkvtoolnix: upgrade to 70.0.0
https://mkvtoolnix.download/doc/NEWS.md
# Version 70.0.0 "Caught A Lite Sneeze" 2022-08-14
## New features and enhancements
* MKVToolNix GUI: the user can now control where the job queue files & the
preferences INI file are stored via environment variables. If set, the
variable `MKVTOOLNIX_GUI_STATE_DIR` can point to a directory where the GUI
stores both the job queue sub-directory and the preferences INI file. If you
only want to relocate the preferences INI file, you can store the desired
file name for the INI file in `MKVTOOLNIX_GUI_CONFIG_FILE`. Implements
#3382.
* MKVToolNix GUI: when adding directories via drag & drop/copy & paste the GUI
will now offer the user the option to create one multiplex settings tab per
directory & adding all files from that directory to the corresponding, newly
created tab. Implements #3371.
## Bug fixes
* mkvmerge: AV1 OBU parser: fixed identifying files that only contain single
frame. Fixes #3380.
* MKVToolNix GUI: multiplexer: when reading color parameters from identified
files that are floating point numbers (minimum/maximum luminance, projection
pitch/roll/yaw) the numbers will be formatted in floating-point notation
instead of scientific notation as mkvmerge only supports the former. Fixes
#3368.
* MKVToolNix GUI: multiplexer: color parameters that are floating point
numbers (minimum/maximum luminance, projection pitch/roll/yaw) will only be
set to a value during identification if the identification actually contains
the property, and not to 0 anymore if it doesn't.
## Build system changes
* Several merge requests where accepted that improve compilation on MSYS2 on
Windows. Note that this build type isn't supported.