now the files are equal

DF Update: Use common CMake version so Darwin handling is correct in PX4

Update DF to use proper constants

Update DF

Output CMake version

Code style fix

-the previous item altitude wasn't valid if switching from LOITER ->
MISSION
-fixes #5395

This brings support for the messages MISSION_REQUEST_INT and
MISSION_ITEM_INT which raises the lat/lon accuracy for waypoints.

This reset the cruise speed which can be set by mission items/waypoints
to set a custom speed. Once, switched out of mission, it makes sense to
use the speed set by the param again.

The px4_os_add_flags defined in cmake/posix/px4_impl_posix.cmake did
add (threading) libraries to added_exe_linker_flags, which subsequently
end up in CMAKE_EXE_LINKER_FLAGS and then have no effect because those
flags are passed to the linker before any of the object files and static
libraries.

Those libraries are already added correctly in the corresponding
src/firmware/*/CMakeLists.txt files (for qurt, nuttx AND posix).

I left in the non-library linker flag '-pthread' for the bebop board,
although it seems very weird to me that this is needed (is it?).
If that is needed then it seems weird to link manually (that is,
src/firmware/*/CMakeLists.txt) with -lpthread.

For linux/g++ -pthread is added to the CXXFLAGS as it should be:
this causes the compiler to define _REENTRANT which is needed
for (the interface of) certain libraries to become thread-safe.
Offically one also can just pass -pthread to the linker, which then
causes the right libraries to be linked, but just linking with
-lpthread -lm -lrt works too.

I ran into this while adding support for libcwd, which explicitly
complains that _REENTRANT isn't defined when trying to link with
the thread-safe version of libcwd (-lcwd_r) and then tells you
to use -pthread.

* geofence messages too frequent

* geofence horz/vert disable with 0 instead of -1

-closes #5430

* Allow Niga to be disabled from command line

* Add a build all nuttx targets

* VTOL transition switch parameter checking

* Code style