various changes, hw11 done

  * ajax loading images for image_markup loads and uploading
  * starting css and styling
  * nested template for imageshare in app, for styling etc
  * img_ids now used in urls and redirected when special=latest/first
  * image select page with ajax loading (way too slow otherwise)
  * paths from /static/images/ now all handled as images
  * hw11 done