Use QImageReader's auto transform feature for JPEG images
Summary:
QImageReader can rotate JPEG images according to their
orientation since Qt 5.5.
Reviewers: Gwenview, muhlenpfordt
Reviewed By: Gwenview, muhlenpfordt
Subscribers: muhlenpfordt
Tags: Gwenview
Differential Revision: https://phabricator.kde.org/D15238