- fix data per photo (additional info into tphoto)                     - DONE
- load data into additional info when plugin starts                    - DONE
- change data when a new photo is selected                             - DONE
- manage data per photo                                                - DONE
- test on enabled group instead of number of photos > 0                - DONE
- add a button to save settings as default (additional info settings)  - DONE
- check update on size, sometimes it's not as expected 
  (suppose same odd behaviour as gwenview and digikam)
- improve dialog gui too big i believe
- clean code
