* The minimum GIMP version for this XCF is always written down when it
  is GIMP 2.8 or over.
* The list of features warrating the minimum version is now listed in an
  expander container rather than as tooltip (making the list actually
  discoverable!).
* The warning on compression is now displayed as its own text under the
  checkbox (only when checking the box actually changes anything
  compatibility-wise), and not as additional text to the minimum GIMP
  version label. Otherwise it had far too much weight on the minimum
  compatible GIMP version text and people were wondering what it meant.
  We should not tell people what the checkbox cannot do (it cannot
  improve compatibility in some cases), only what it can do (it can
  improve compatibility in other cases).
* Update the feature list real-time when checking the compression box
  (making it even more obvious that tile compression may have a say in
  compatibility).
* Metadata info is still added on the GIMP version label as it does not
  limit compatibility of the XCF file itself.