Misc notes about the images:
- rows 6 and 7 are not used (they were intended for an experimental feature, now abandoned)
- not all images in row 8 are really needed (icons 1, 2, 4, 5, 7, 8 and 10 are certainly used)
- in row 9, I couldn’t find the use of icons 2, 3, 4 and 6
- in row 10, I couldn’t find the use of icon 5
- the last two rows (all the cursors and the Audacity logo) appear to me not to be used (please help me confirm this)