Updated Slovenian translation
Add a contextual help button in the render dialog to explain container formats
Allow entering a frame number into the time widget

The downside to this is that we don't seek live while typing anymore:
the frame number being typed would always get overridden by timecodes.
Users have to activate the text widget (press Enter) to seek with it.

On the other hand, this is compensated by the fact that we also seek
when the user defocuses the text widget.

Fixes bug #684236
Updated Polish translation
project: Make the "Restore from backup" dialog modal to the main window
Add a button to toggle a "gapless" (auto-ripple) timeline mode

Fixes bug #668056