QSerialPort buffering too slow on Windows.

Conflicts:
	src/uas/QGCMAVLinkUASFactory.cc
	src/uas/QGCMAVLinkUASFactory.h

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.

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.

Make Qt Quick Widgets Mac specific. Apparently its so new the Qt folks have not figured out cross platform config entirely yet

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

Fix HIL link reconnect issues due to missing threading flag usage, warn user about missing config and take him to config view if necessary

Fix HIL link reconnect issues due to missing threading flag usage, warn user about missing config and take him to config view if necessary

Recent threading changes have broken both of these. They will be fixed
in a separate pull request. Also added new CmdLineOptParser.cc/h