GD thumbnailer does not respect EXIF image rotation or autoOrient flag

[Karl-Holten]

When using GD for image processing and thumbnail generation, the config.php autoOrient flag does not work. This results in many phone images being incorrectly oriented on their sides for when using GD as a thumbnailer.

Here are the forum posts and corresponding issue for the ImageMagick driver fix:
https://forum.omeka.org/t/all-options-of-the-file-local-config-php/5485
#1209

Note that while the Imagek.php and Imagemagick.php no corresponding change was made to GD.php. A method should be defined for GD thumbnail generation similar to the one in the Imagek driver, so that image rotation metadata is handled properly.