to prevent a setpoint step when moving the stick over the border of the deadzone
and to enable very small inputs even from a control stick that needs a big deadzone

since it's only used in sensors module (otherwise it could get pruned)

If param_find() returned PARAM_INVALID, and this was directly passed to
param_get(), param_get_value_ptr() returned null and we read garbage data
(or segfaulted on systems with virtual memory).
On px4fmu-v2, this happened for the param ATT_VIBE_THRESH in sensors.
Because of the recently added parameter scoping, this param got pruned, as
it's defined in attitude_estimator_q.

credits for finding this go to Jeyong Shin (jeyong).

This is according to the updated mavlink spec to deconflict the definition
with APM.

Probably this was a merge error.

because it is definitely something that needs to be allowed to tune or disable for different application scenarios

The maximum number of missions was increased in almost 8 times in
recent commit: 9369262e navigator: allow more mission items.

As this board loads missions in RAM, now it don't have enough memory
to allocate causing dataman start to fail, so mark it as a memory
constrained system and reduce the number of maximum missions
supported.

STM32 pins are not exposed in AeroFC, so lets save some memory here.

WARN  [load_mon] tap_esc_main low on stack! (284 bytes left)

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

Even for well calibrated RC sticks 5% stick movement is a too small margin for the end user that might not land because of this.
15% is still clearly restricting the stick far down.

Rattitude: set default threshold for multicopter rattitude mode to 0.8 which enables it right away when selecting it