Disable the active WP setting in the edit list, as its super error prone - only allow it in the view list and switch between views based on activity on the system / UI

flightgear HIL: also use default Scenery directory besides terrasync

Warnings fixes

Add libudev-dev to linux build requirements

This removes a race condition between both qwt and qt against math.h on
windows with _USE_MATH_DEFINES set. If math.h comes after qwt or qt
math headers the math defines will be redefined. Really nasty to track
down and ordering problems. So instead I just removed using math
defines on windows and fall back to asin definition of M_PI_2. This
will have some slight perf impact since it calls function instead of
using constant. But I doubt on any of today’s machine it really makes a
difference.

Number of warnings is low enough now to let them come through. Lowered
Windows warning level the /W3 to be more consistent with OSX/Linux
level of warnings. Removed /WX from Windows build. I’ll put it back
once everything is cleaned up.

Conflicts:
	src/comm/QGCFlightGearLink.cc

QGC depends on libudev-dev to build, include this in the list of packages to install.

Airframe config: fixed hexa copy and paste error

PX4 config: Remove the specialized throttle handling - this needs testing, but doing the math on paper it doesn’t look like a special case is needed / wanted here.

Use the reversed values for the four control channels as well. Not using them would make the display very confusing.