WebSubmit: rotate created icons according to EXIF

* When creating icons, rotate the created icons according to
  the Exif "Orientation" metadata of the original photo.
  Closes #1516.

Signed-off-by: Jerome Caffaro <jerome.caffaro@cern.ch>
Reviewed-by: Ludmila Marian <ludmila.marian@gmail.com>
Merge pull request #17 from ludmilamarian/jerome-1516

WebSubmit: rotate created icons according to EXIF