initial commit with waterfall widget code and demo
fix colour of selected marker
select other marker when removing selected marker
fix fshift resetting
set fshift min/max
handle versions switching to major.minor
QComboBoxPlus generic widget
fix version comparison (str compare bad)
fix device controls during playback, fshift range
spin boxes for trace top/bottom
auto freq by default in all modes (added dev option to disable)
avoid crash when setting fstop <= fstart
more room for mode combo
avoid squishing widgets with a larger minimum height
no trace - button, use off in combobox instead
Merge branch 'ui-improvements'
Merge branch 'version-major-minor'
fix plot scroll vs. control freq issue
support old playback files
trace controls thin line version