Feature request: Lock camera orientation #434

When I want to make a picture holding the phone parallel to the surface (mostly in landscape mode), the app switches between landscape and portrait mode. This is very annoying when making pictures of tens of pages of documents, I either have to constantly look whether the app changed orientation and try to correct it OR later rotate the images. (and no, I don't want to use a scanner)

In my opinion the best option would be to sync the camera orientation with the state of Android's auto rotate. But since every camera app has auto rotate enabled and most people rely on it, a realistic solution could be to add an 'Auto rotate' or a 'Lock orientation' toggle in the settings.

Related issue: #55 (not fixed)