title: Delphi TPngImageList save/load from file
body: <p>I'd like to load and save TPngImageList (Delphi7 version, PngComponents) from/to file (better single PNG file for all 20 png icons in image list). I can't find <code>LoadFromFile/SaveToFile</code> methods. </p>
  
  <p>How to do it?</p>