Update to version 0.7.0, which appears to be another fork of the no longer
maintained version 0.5.4 (or the already forked 0.6.2).
This version adds support for qt5 (port option, default remains at qt4) and
is claimed to be compatible with ffmpeg-3.x (not verified, yet).

PR: 214193
Reported by: jbeich (ffmpeg-3 exp-run)