Revised the DLLs that are copied post-compilation so that QGC.exe can run.
Improved robustness by quoting all filenames/paths.

Remove isnan() and isinf() templates from QGC.h for Windows builds

Some build improvements

Flighttermination mavlink command

Remove isnan() and isinf() templates from QGC.h for Windows builds, this
generates errors (already defined in math.h).

Also added Qt version check.
And made the platform/toolchain check a little more descriptive.

Broke windows compilation.

Add msvc2013 to build types

First QT5 PR, all core functionality works

Add debug output for when voice initialization fails on Windows

Removed or annotated existing commented-out code

Clean up logic for saying emergency text.

Previous code didn't properly check for if speech was enabled.

Mavlink submodule

Some functionality was lost, will need to be fixed in a later commit.