Italian translation updated
Update French translation.
Merge pull request #556 from bartokk/master

Italian translation updated
Lens IOP: add autodetection, based on fact "did user or did not changed anything in GUI from autodetected values"
Merge pull request #548 from LebedevRI/lens-autodetection

Lens IOP: add autodetection
Some more GUI fixes

- Try to keep background grids crisp in custom widgets.
- Put a subdued dt logo into the empty widget of zone system.