From discussion #427.

Questions:

• Should there be a separator, like "and"? So it would read as "Field between X and Y" instead of just "Field between X Y". If so:
  • Should it be a full-blown component or just a translatable string?
  • What class(es) should be added by default?
  • Should it be hidden by default, or "" instead of "and"?
  • Should it be configurable by field?
• Is the listsAsArrays prop enough to manage the way the handleOnChange prop is called from within the default component?
  • Do we need a parseNumbers-ish prop for <QueryBuilder /> that attempts to set value to a number?

Similar enhancements (plus add/remove controls for a dynamic list of value editors) are needed for "in"/"notIn".