insert SVG as file instead image: studip sends it as application/octet-stream
post_file URL for JS drag'n'drop is dynamically set by storing it in hidden <input> value via PHP
pretty-print html view: adding newline after specific tag (br, p, h1, ...) when switching to html view
target="_blank" and rel="nofollow" are no longer removed
removed debug code for figuring out why title attributes are removed from img (wysihtml5 removes them)