find (and replace) components

Find all components of a given glyph, and optionally replace it by another glyph.

RF3 RoboFont 3 code which still works in RoboFont 4. Not updated to the new RoboFont 4 APIs yet.

find
the name of the base glyph
references
a list of glyphs which reference the base glyph
mark color
choose a color to mark selected glyphs
mark
apply mark color to selected glyphs in the list
new base glyph
the name of a replacement base glyph
replace
replace base glyph by new glyph in the selected glyphs