Move to 64 bit, MSVC 2017

Android gstreamer bitness

Guard against no geometry being set

Video is still not being displayed, for some reason

Fix no GST builds

This solves the issue where the video is lost for a few seconds  after
clicking record as the filesink attempts to preroll but doesn't have a valid buffer,
stalling the whole pipeline.

Updating the currently used version of GStreamer

Updated MAVLink to handle video stream types (auto discovery)

On desktop (Ethernet connection), the ground unit pushes UDP directly, which makes the use of an actual "Link" not possible. Instead, I've moved all of Taisync support to a "manager" owned by QGCToolbox.
Added a Taisync settings with some basics already wired and running.