More comprehensive testing of FileManager error/edge cases

Cleanup some unitialized variable issues pointed out by Valgrind

Specifically much better testing for the handling of:
- Ack responses not being sent by server
- Getting Nak’s back from commands
- CRC failures

Also changed file validation to take into account Mock Server no longer
sending file length in first byte of file.

Also changed the downloaded file contents to not include the file
length in the first byte. This makes the code a bit less confusing.

Valgrind fixes

Delete outdated and unused (all) SLUGS-autopilot-specific code

Changed to get the current voice properties, then modify then and set new ones.

Changed to get the current voice properties, then modify then and set new ones.

File manager Unit Test back on

When unit tests are being run in TeamCity the host box can end up being
very bogged down with other builds. So need to up wait time, to take
into account CPUs grinding.

Need to disambiguate from video stream messages

Qt5 qmake seems to leave this handing around

Found by valgrind.

Found via valgrind.

Found by valgrind.

Temp disable of FileManager unit test

This is to get TeamCity up and running again. This unit test fails only
in TeamCity for some currently unknown reason. One TC is back up, I’ll
revisit and turn it back on.

Qtquick2

Remove QtConcurrent from repository

mavlink: submodule updated

Fix remaining Windows issues on Qt5