more but smaller pages

• split tiles page into pattern, stitches and droste that are print friendly on their own and better self explaining
  note that the tiles page won't be maintained any more and will be dropped in the future.
• paint threads in droste diagrams
• free choice of color for threads
• highlight stitches in thread diagrams
• minimize / maximize buttons replace step wise in/de-crease for diagram sizes
• stitch gallery with color code symbols
• fully visible thread starts make a bigger target to highlight threads
• less invisible floating nodes in first droste pair diagram
• (i) buttons replaced by drop down help menu