LandDetector FW: Fix param min/max values and descriptions as well as some variable names which were wrong/outdated (#9708)

If the PX4FMUv2 board does not have the v5 uploader, it's not possible
to check the silicon revision to make sure it's safe to upload the
firmware which is more than 1 MB. However, if the user is sure the
silicon revision is not affected by this errata, he can upload the
firmware using px4_uploader.py with --force argument. This commit adds
`force-upload` make target to do it more convenient way.

Signed-off-by: Andrei Korigodski <akorigod@gmail.com>

* ecl: Update to version allowing use of flow sensors without gyros

* msg: Update description for optical_flow

Adds advice for publishing gyro rate integral message when no rate gyro is fitted.

Uninitialized `_ping_stats.last_ping_time` caused ping statistics to be printed even when no ping was received.

The uorb subscribe logic got changed for queued topics with
https://github.com/PX4/Firmware/pull/9436, meaning an orb_subscribe will
return past messages as well now.

This lead to an error 'Command denied during calibration' for the previously
received calibration start command.

    - sitl_gazebo in PX4/Firmware (ebc40067): https://github.com/PX4/sitl_gazebo/commit/8a3166bf5d315274cfd503a75880e9837faa9694
    - sitl_gazebo current upstream: https://github.com/PX4/sitl_gazebo/commit/b5a92095bfb1b6a218a80f58ad9fe09c89ef4598
    - Changes: https://github.com/PX4/sitl_gazebo/compare/8a3166bf5d315274cfd503a75880e9837faa9694...b5a92095bfb1b6a218a80f58ad9fe09c89ef4598

    b5a9209 2018-06-10 TSC21 - travis_ci: Add OSX build

This sets all channels to zero, including unused channels. Any consumer of the data using the channel count will not see a difference, but this is helpful to avoid confusion in log analysis.

    - apps in PX4/Firmware (1bc4a73eaacdb40f7d3f5ebd11882913b541b419): https://github.com/PX4-NuttX/apps/commit/7e2f17db4e770e65ee39b1a964cf4644720d976c
    - apps current upstream: https://github.com/PX4-NuttX/apps/commit/36806ba3d84c0fa07ed86857d4c92a997b7cd194
    - Changes: https://github.com/PX4-NuttX/apps/compare/7e2f17db4e770e65ee39b1a964cf4644720d976c...36806ba3d84c0fa07ed86857d4c92a997b7cd194

    36806ba 2018-06-06 Beat Küng - nsh_parse.c: fix 'while' and 'until' loop condition

    - v2.0 in PX4/Firmware (a19fecad): https://github.com/mavlink/c_library_v2/commit/653ac745a57794a38c831f1ff296066a2e09c09b
    - v2.0 current upstream: https://github.com/mavlink/c_library_v2/commit/033fa8e7a4a75a0c3f17cea57e3be8966e05f770
    - Changes: https://github.com/mavlink/c_library_v2/compare/653ac745a57794a38c831f1ff296066a2e09c09b...033fa8e7a4a75a0c3f17cea57e3be8966e05f770

    033fa8e 2018-05-24 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/d8ea87b9c6173ad72a032219588e302eb8cb212a

   Refactored for efficiency and simplicity.

contains:
- https://github.com/PX4/ecl/pull/460
- https://github.com/PX4/ecl/pull/462

  to include [BACKPORT] Merged in kekiefer/nuttx/stm32f7-serial-fix-tiocssinglewire-upstream

Because _pins[i] is set from parameter value - 1

   This is the root cause of https://github.com/PX4/Firmware/issues/9461
   The _pins array was initialized to -1. It was used to index the
   _gpios array. The value at _gpios[-1] was a number that mapped to
   Analog mode on Port A pin 0. These is the UART4_TX pin and was
   being reconfigured by the fault in the camera_trigger to an
   alaog input.

   This reverts commit a62a71f4.
   The root cause was the camera trigger passing invalid pin
   configuration setting overwriting the UART4 TX pin setting

computational load in optical flow simulation

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

Fixed-wing autoland: Fix bug that could cause a steep pitch increase and thus aircraft stall during the flare (#9674)

In precland the copter may switch to horizontal approach state with an
old landing target pose message.