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

There is a *bug in Qt5 (as of 5.3.1) where QMenuBar::items don't inherit their background colors, but revert to default system styling. The work around is to explicitly color their backgrounds.

Various fixes

Our included make file doesn't build for 64-bit.
We actually need better selection on Windows and Linux platforms for building 32-bit or 64-bit versions.

I don't think it's needed anywhere in QGC since this has been a bug for a long time.

This causes problems for some systems with Qt5 and Qt4 installed (like Fedora 20).

mavlink submodule: use latest pixhawk headers

Remove protobuf hacks

Fix videotransmission

SLUGS has maintained their patches out-of-tree for a long while now.
These will eventually get merged back in, but it'll be easier to evaluate them as fresh commits instead of modifications to this old & dead code, so we'll delete this for now.