* VTOL trans: changed that now in transition for both MC and FW the corresponding (correct) attitude controller is running
* attitude setpoint for stabilized mode is generated by tailsitter.cpp
* reset yaw setpoint during transition to avoid big yaw errors after
transition back to hover
* VT_TYPE parameter: added "reboot required" metadata

    - ecl in PX4/Firmware (fa1fbed24633aef7985a128ebd4d19a7f6a4d108): https://github.com/PX4/ecl/commit/c4492b17c1d7bb9b74011efa9890452b091421e8
    - ecl current upstream: https://github.com/PX4/ecl/commit/a27a43eafa8f4dd514e89984f5394260a36ea4f6
    - Changes: https://github.com/PX4/ecl/compare/c4492b17c1d7bb9b74011efa9890452b091421e8...a27a43eafa8f4dd514e89984f5394260a36ea4f6

a27a43e 2019-05-01 Hamish Willee - Fix up link to EKF docs
3f69189 2019-04-04 Mohammed Kabir - EKF: control: stop vision yaw fusion on timeout

Commander initially publishes a tune_control topic set to 0, which can
interfere with the startup tone (as happening on the Pixhawk Cube).

To be able to still infer the direction of the thrust vector we
limit it to a minimal length even if MPC_THR_MIN is set to zero.

Note: This is a hotfix for certain specific applications.
The direction of the thrust vector in this corner case is very
likely to get into the tilt limit which is generally undesired.

A low gyro cutoff is needed for most medium/large size drones as the structural natural and blade-pass frequencies are low.
A higher value is still desirable for small platforms surch as racers
or well isolated autopilots and should be tuned by the user.
Specific values for config files are untouched.
The cutoff filter for the D term is disabled here as the required
cutoff frequency for the default D term of the rate controller is higher
than the gyro cutoff. In that case, enabling the D term cutoff would
just add some undesired phase lag to the derivative.

 - minimap size and display
 - title bar show file path and if modified
 - disable natural language search (sends keystrokes to Bing)

    - jMAVSim in PX4/Firmware (7ec6f0dc): https://github.com/PX4/jMAVSim/commit/79586deda5176c37de7804904f2553c8547edc4a
    - jMAVSim current upstream: https://github.com/PX4/jMAVSim/commit/ae1593d0c8d6f3860081dff04ada1cacda4c8087
    - Changes: https://github.com/PX4/jMAVSim/compare/79586deda5176c37de7804904f2553c8547edc4a...ae1593d0c8d6f3860081dff04ada1cacda4c8087

ae1593d 2019-04-30 Julian Oes - Merge pull request #100 from PX4/fix-port-default
9de8f86 2019-04-29 Julian Oes - Simulator: fix default for QGC and SDK link
d42efaf 2019-04-29 Julian Oes - Merge pull request #99 from PX4/pr-add-sdk-port
7d0bebb 2019-04-26 Julian Oes - Simulator: fix copy paste mistake
a94816e 2019-04-26 Julian Oes - Simulator: add MAVLink UDP port for SDK
6a9634b 2019-04-26 Julian Oes - Visualizer3D: ran fix_style.sh

    - mavlink v2.0 in PX4/Firmware (0d543e29bb4535df9654c1f3a7c8f0712e81a120): https://github.com/mavlink/c_library_v2/commit/d8c4e5def38f2ff6079087e579693b4bd9552584
    - mavlink v2.0 current upstream: https://github.com/mavlink/c_library_v2/commit/57000134021fb8d5c2c6281e3783ce29bb35bc17
    - Changes: https://github.com/mavlink/c_library_v2/compare/d8c4e5def38f2ff6079087e579693b4bd9552584...57000134021fb8d5c2c6281e3783ce29bb35bc17

It looks like the atomic builtins are not available using QuRT and the
Hexagon toolchain, so our best bet is to use `volatile` for the atomics.

When sih (simulation in hardware) was compiled for Snapdragon, we got
the linking problem below. I'm not sure why, supposedly the symbol
`double sin(double)` is missing.

undefined PLT symbol _LSin (705) /libpx4.so (symbol.c:303)

See https://github.com/mavlink/qgroundcontrol/issues/7360

Signed-off-by: Claudio Micheli <claudio@auterion.com>

It implicitly converted STRINGS to STRING.

This fixes a potential dead-lock when 'uorb status' was used via MAVLink
shell.
The dead-lock chain is: DeviceMaster::lock() -> printf -> output to a pipe,
which blocks until a reader reads the data. In that case it's mavlink.
If mavlink makes a call that requires DeviceMaster::lock() (such as
orb_exists), it dead-locks.

This patch moves all printf's out of the locked state.

This should fix the regression where the mag values were not properly
initialized and caused EKF2 to stop in CI.

It is expected that Iris auto-disarms the same as in SITL.

- when either terrain data was temporarily not valid (flying at high
distance to the ground) or the vehicle was not close to the ground
(_param_ekf2_gnd_max_hgt) the ekf switched to using the land detector
ground effect flag.

Signed-off-by: Roman <bapstroman@gmail.com>

    - mavlink v2.0 in PX4/Firmware (a26c25ca5bd0168dd2274dd8aa0392aba10feff2): https://github.com/mavlink/c_library_v2/commit/c6ab0459343c78a6a424514b5f64fa65d8cc0cf8
    - mavlink v2.0 current upstream: https://github.com/mavlink/c_library_v2/commit/d8c4e5def38f2ff6079087e579693b4bd9552584
    - Changes: https://github.com/mavlink/c_library_v2/compare/c6ab0459343c78a6a424514b5f64fa65d8cc0cf8...d8c4e5def38f2ff6079087e579693b4bd9552584

- takeoff help is used for fixed wings, it increases the altitude setpoint
after a launch. A vtol does not need this as it's already sufficiently
high up in the air.

Signed-off-by: Roman <bapstroman@gmail.com>

This reverts commit 4a71984f.

This reverts commit 585b9d8c.

This way we prevent a big dip due to TECS in altitude when the
transition happens at 10 m/s already. Apparently the rule of thumb
is to set this transition speed at the same as airspeed cruise speed.

The noise for airspeed is now applied on the Gazebo side and we can
remove this hack.

Includes:
- Fix for vibration on ground for standard_vtol.
- Noise for diff pressure / airspeed on Gazebo side.
- Fix for macOS magnetometer plugin linking error.

the condition to enter the rc mode switch evaluation was neglecting
the first connection of an RC when "no RC switch changed". this means
depending on the actual initialization values of _last_sp_man and the
desired mode preselected on the RC while connecting it would not get
evaluated.