Less verbose ffmpeg output, insert newline, switch to output on fail

[humdingerb]

• The parameter "-loglevel error -stats" gets rid of too verbose output while still sending progress info.

• More readable output formatting by adding a newline after every progress output.

• Show "Output" tab if encoding failed and scroll to bottom.

[humdingerb]

@andimachovec, or do you see a need to print all that ffmpeg configuration text-wall?

[andimachovec]

do you see a need to print all that ffmpeg configuration text-wall

No, not at all. I just didn't find (or search thorough enough to find) the right option to get rid of it. That's a good improvement and makes the errors easier to find in the output tab.