- v2.0 in PX4/Firmware (21f6ca4a): https://github.com/mavlink/c_library_v2/commit/fe2349dea9a88fb5b873eff2a59a88125943fd61
    - v2.0 current upstream: https://github.com/mavlink/c_library_v2/commit/d8fcf0a694dc11b3f83b89a0970e3d8c4e48d418
    - Changes: https://github.com/mavlink/c_library_v2/compare/fe2349dea9a88fb5b873eff2a59a88125943fd61...d8fcf0a694dc11b3f83b89a0970e3d8c4e48d418

d8fcf0a 2018-08-30 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/580a9ce77f3653d04937c9703dbd7fb31bf0ef33
189a1d8 2018-08-27 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/1a55f0bf6101d87ee50a92869c6a31a855526fd2

    - matrix in PX4/Firmware (468f28463eabc30843e606546d642adc1a62fe10): https://github.com/PX4/Matrix/commit/b815fc97c4e686a93a8074f27d1830a031b0d38d
    - matrix current upstream: https://github.com/PX4/Matrix/commit/dc3af8097798881b9b2e72a029a3c6c10abd059b
    - Changes: https://github.com/PX4/Matrix/compare/b815fc97c4e686a93a8074f27d1830a031b0d38d...dc3af8097798881b9b2e72a029a3c6c10abd059b

dc3af80 2018-08-27 Daniel Agar - constructors use array size rather than pointers
f1bee77 2018-08-27 Daniel Agar - use default constructors and skip unnecessary initialization
1bcf48b 2018-08-30 Daniel Agar - Quaternion from_dcm don't pass by value

    - ecl in PX4/Firmware (95b83ba29715c067a30cb9501cab51264db502f1): https://github.com/PX4/ecl/commit/56b8bb08a16f0e86f7c7dfe458f0d2d3082e92e4
    - ecl current upstream: https://github.com/PX4/ecl/commit/3c74dc2ce1002db5b68a833fdd0aa964210e91f5
    - Changes: https://github.com/PX4/ecl/compare/56b8bb08a16f0e86f7c7dfe458f0d2d3082e92e4...3c74dc2ce1002db5b68a833fdd0aa964210e91f5

    3c74dc2 2018-08-30 Daniel Agar - ECL_Controller base needs virtual destructor
0d39072 2018-08-30 Daniel Agar - EKF add missing header guards
a6a1edb 2018-08-30 Kabir Mohammed - EKF : Fix type of flow data navigation variable (#499)
a53ad9c 2018-08-25 Paul Riseborough - EKF: Add missing optical flow ground motion protection

   - nuttx in PX4/Firmware (0a1a2025402a387cde88132c6f8d8cc7237d2e6b): https://github.com/PX4-NuttX/nuttx/commit/bf8cce85c3f9310bcff8cdd1d979270419782a6e
    - nuttx current upstream: https://github.com/PX4-NuttX/nuttx/commit/e3b5b667aee16a699ecd6605f2d2a4adc6e95c17
    - Changes: https://github.com/PX4-NuttX/nuttx/compare/bf8cce85c3f9310bcff8cdd1d979270419782a6e...e3b5b667aee16a699ecd6605f2d2a4adc6e95c17

e3b5b66 2018-08-31 Daniel Agar - [BACKPORT] Merged in dagar/nuttx/pr-stm32f7_stackcheck-upstream (pull request #714)

 - The first waypoint contains the vehicle current position and the desired velocity setpoint

  Use CONFIG_ARMV7M_STACKCHECK to add the instrumentation
  for runtime stack checking

  To enable coherent runtime stack checking use the boards
  CONFIG_ARMV7M_STACKCHECK setting

 - this is shared by both the FW position controller and navigator's
   missiong feasibility checker

Not needed anymore

This is all done through posix_sitl_default.cmake and env variables:
- PX4_ESTIMATOR
- replay

Generally exit() should not be used on Posix, because it exits the whole
program instead of only the task.

On POSIX it exits the process.

   On FW with a px4io bin file, but not a px4io do not error

   Use tune control and have all paths in rcS indicate tunes

    Adds a single file definition to provide a single point to add
    new tunes and clearly understand, the useage: it need to be
    stopped will it not allow interruption.

	Refactor to use the tune_control interface

    Since tune control came in this driver does not have a
    have a test based interface. The module Documentation
    has been moved to tune_control

    minor cleanup and assert on workque delay of 0

    Since tune control came in this driver does not have a
    have a test based interface. The module Documentation
    has been moved to tune_control

    Since tune control came in this driver does not have a
    have a test based interface. The module Documentation
    has been moved to tune_control

    minor cleanup and assert on workque delay of 0

    Since tune control came in this driver does not have a
    have a test based interface. The module Documentation
    has been moved to tune_control