Ctrl+shift+drag message in Lubis viewer to rotate images

[Test Link] (http://mf-chsdi3.dev.bgdi.ch/kan_message_rotate_button/luftbilder/viewer.html?lang=de&layer=ch.swisstopo.lubis-luftbilder_farbe&title=No+de+l%27image&height=17003&width=16574&bildnummer=20057110431695)

See issue #918