LandDetector FW: Fix param min/max values and descriptions as well as some variable names which were wrong/outdated (#9708)

* 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.

Subsystem_info status flags & checks: Separate the functionality to a) set the health flags inside commander and b) to publish them from external modules

Subsystem_info status flags & checks: 1) Set health flags in commander directly instead of publishing via uORB 2) move publish_subsystem_info into lib/ folder"

Subsystem_info status flags & checks: Switch back to uORB for inter-process communication, handle GPS checks completely inside ekf2, add distance_sensor checks

Subsystem_info status flags & checks : Initial commit, updating the health flags in a centralized way mostly in commander and the votedSensorsUpdate function.

* Add return to land to mission

This method uses the planned mission for rtl. If a landing sequence
is present it will continue the mission and land. If not it will
fly back the mission and loiter/land at the home position.

As per issue #9428, this code change locks down the termios configuration
for the UART to non-canonical, binary tx/rx, 8 bits, 1 stop bit, no parity.

- genmsg in PX4/Firmware (3ed093ba): https://github.com/ros/genmsg/commit/3cea1fe528cd7ecdae7f8930fe90451271aec937
    - genmsg current upstream: https://github.com/ros/genmsg/commit/a189fc78558e7276df59d2961cfe4f8b4de08a8b
    - Changes: https://github.com/ros/genmsg/compare/3cea1fe528cd7ecdae7f8930fe90451271aec937...a189fc78558e7276df59d2961cfe4f8b4de08a8b

    a189fc7 2018-05-01 Dirk Thomas - 0.5.11
c641725 2018-05-01 Dirk Thomas - update changelog

 - px4_add_module now requires MAIN
 - px4_add_library doesn't automatically link

 - this flag often results in hiding useful information, or adding
   useless information to the mavlink console

Switch to the high latency telemetry, if available, if every low latency link is lost. Switch back if any low latency link is regained. Only indicate that all links are lost if all high and low latency links are lost. Allow different timeouts for high and low latency links.

Allow enabling/disabling transmitting data from all mavlink instances
with a specific mode/type. When disabled the instance can still receive
data. The uORB message used is the vehicle_command and uses the following
parameter:
param1: Specifies the mode/type of the instances to enable/disable transmitting
param2: Boolean to indicate if transmitting should be enabled or disabled

_uorb_topics_list was marked as 'const char *' array, which means the data
of the array was not actually const and thus landed in the data section
(so in RAM instead of FLASH).
The size of the array is 436 bytes.

 - indent field print with tabs instead of spaces
 - print a newline before printing a nested field
 - cmake add generator dependencies

- true airspeed innovation and variance
- sideslip angle innovation and variance

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