Update translations from Transifex:

 - Basque
 - Catalan
 - French
 - Spanish
 - Ukrainian
Add a Finnish translation.

The composition of the translation team can be found on Transifex: https://www.transifex.com/organization/mpc-hc/team/3979/members/fi/.
MiniDump: Ensure the message about the crash is always shown.

It wasn't shown when a crash occured before the main window was created.
LAV Filters: Distribute CHANGELOG.txt, README.txt, COPYING files (PoC).
Don't force any background color for the Shockwave graph.

This commit fixes #1747.
WebUI: Inform the web interface that no audio stream is available.
WebUI: Make use of new [hasaudio] info.
What the hell was intended here?!

Trying to make some sense of that code. Without much luck so far...