Various usability improvements were implemented for the Qt figure options editor, among which: - Line style entries are now sorted without duplicates. - The colormap and normalization limits can now be set for images. - Line edits for floating values now display only as many digits as necessary

to avoid precision loss. An important bug was also fixed regarding input validation using Qt5 and a locale where the decimal separator is ",".

• The axes selector now uses shorter, more user-friendly names for axes, and does not crash if there are no axes.
• Line and image entries using the default labels ("_lineX", "_imageX") are now sorted numerically even when there are more than 10 entries.