This is necessary to make the space for UAVCAN in memory and doing it this way avoids negatively impacting users who do not use UAVCAN.

  Recover 16 bytes. Size of debug max message is 40 so limit
  the usart tx buffer to same size.

   This removes the unused input capture capabilities from the px4io
   and saves 128 bytes of ram.

This avoids burning significant memory in a configuration that is not actually using parallel tasks

The app reached the check limit and needed a bit more headroom.

because we need a workaround for the broken auto takeoff logic which can start the vehicle with a loiter setpoint
in this case the very first moment is still a jump but then it gets taken over by the fix gradient ramp
this can basically be reverted after the auto takeoff logic is fixed

currently when the vehicle is landed again (not after bootup) the core position controller does not run anymore
therefore the velocity limit ramp in some cases did not get reset correctly

speed limiting in auto takeoff mode only needs to be limited when the user did not take over

adresses:
there were setpoint twitches at the beginning and end of my smooth takeoff routine
it was to slow and not configurable
it was only available for automatic takeoff

mc_pos_control: switched auto takeoff to clean position control to takeoff point with gradual velocity limit
auto takeoff  was pretty chaotic and bypassed the velocity controller until some magic condition
the goal of this approach is to make the behaviour and smoothness more predictable and reuse the exact same logic for manual takeoff

mc_pos_control: pure refactor, split up core position control into velocity and thrust setpoint generation

 - a local implementation was used before which is not necessary

This got introduced with the refactoring in c5e84125

 - fixes #7050