More consistent with Qml usage pattern

PrimaryFlightDisplay: Clear up speed label (now showing airspeed and groundspeed separately to avoid confusion) and add vertical climb label

also adds AMSL output in ft

Removed completely unused variables. Ifdef’ed out variable which is
referenced from commented out code.

- NAN not available in windows headers, use cross platform friendly
version
- VS compiler does not allow initializing non-integral types in header
files
- ActiveQt libs are already installed by Win Qt4.8.5, no need to build.
Plus this part of the makefile just loops without nmake.exe installed
which is not part of a standard windows box

Altitude splitted to altitudeAMSL and altitudeRelative, speed splitted to airSpeed and groundSpeed. PrimaryFlightDisplay uses airSpeed for FW and groundSpeed for MC.

Start move to single column layout for advanced parameters; Fix
crashing bug in PrimaryFlightDisplay when uas is removed and then
re-added; workaround compiler warning in GeneralBlockPanelKernel,

Impl. Lorenz suggestions wrt one velocityChanged, altitudeChanged, speedChanged signal per reference frame. Impl. CDI on compass disk.