* Fix #1672407 confused by plugin-named files in cwd (or home?) * Fix #1491848 crash when loading new file while transform plugin runs * Fix #1502287 Background remains black after spectrogram layer deleted * Fix #1604477 Replacing the main audio file silences secondary audio file * Fix failure to initialise property box layout to last preference on startup * Fix resample/wrong-rate display in Pane, ensure that right rate is chosen if all current models have an acceptable rate even if previous main model had a different one * Fix "global zoom" broken in previous commit * Some fixes to spectrogram cache area updating (makes spectrogram appear more quickly, previously it had a tendency to refresh with empty space) * Fixes to colour 3d plot normalization