2020 Mar 23
* Fixed poor performance caused by GPIO Widget 60.
* Added Preferences Dialog Help 52.
* Added marker Clear button to Waveform Control Widget 49.
* Fixed "Add Single" marker button not working correctly.
* Added Waveform Control button to zoom out to full x-axis extents.
* Added discrete Waveform Control buttons to toggle signal display 50.
* Added device recovery rate limit. Previous version was spamming the
recovering device which caused more problems.
* Modified command-line to accept all Joulescope package commands.
* Fixed command-line filename argument support 62.
* Fixed current ranging preferences 63.
* Improved handling of empty JLS files and zero length data.
* Resized waveform signal statistics text to fit 54.
* Resized waveform marker text to fit.
* Added feature to move both dual markers on CTRL left click 56.
* Corrected widget heights for Control, Waveform Control, Single Value, GPIO.