Same-site redirects are now relative paths, and a saved page on another site is ignored. The HTTP to HTTPS redirect takes its host from the new SITE_URL setting, and without it the pages refuse plain HTTP.
save_uploaded_file() read, and prune_images() deleted, any path in the
"uploaded" POST field. Uploads now go to UPLOAD_DIR under a random name
that only the session knows.
Replace the short open tags and the removed functions (mcrypt, mysql_error,
salt-less crypt). Decode the reCAPTCHA reply as JSON, turn off mysqli
exceptions, drop stripslashes(), and default missing input values.
Fix the misplaced continue in prune_images().
From the live site: local Noto Sans, a flexible layout up to 1000px, and
a slide-out sidebar menu on small screens. Remove the unused Genericons
font and logo images.
tim