Factor out into `folio-menu-choices'.
Factor out `notify' defuns and switch over to using the dynamic
choices machinery of the base widget.
Tweak widget layout.
Style.
Use `member' for checking existence of a list item.
User proper name of symbol to lookup in the forms database.
Cleanup obsolete code
Make the script filter function available.
Don't re-focus node widget when stepping through occurrences.
Add support for filtering by script.
Add doc-string.
Apply sort to a copy of the list structure as sort modifies it.
Fix doc-string.
Work around misspelled Emacs symbol name.
Add `folio-left-to-right-safe'.
Handle words in RTL text directionality by assuming bi-directional
text for respective widget contents.