autotest: update fg_plane_view.sh for FlightGear 3.0
Plane: moved takeoff code to a new file
Plane: fixed sign of target and nav bearing in logs
autotest: set full logging for plane
AP_L1_Control: wrap the target_bearing
Plane: added 4 new parameters to control takeoff

this gives flexible control for taildragger takeoff
Plane: prevent stalled takeoff with bad TKOFF_TDRAG_SPD1

go to level pitch if pitch rises by 10 degrees
Plane: improve takeoff docs for tricycle undercarriage
Plane: aim for 5 degrees pitch during accel phase of takeoff

this makes it less likely we will get prop strike
Plane: added TKOFF_THR_MAX parameter
AP_NavEKF: Increase divergence test margin based on analysis of more user flight logs

Analysis of copter logs has shown cases with a healthy EKF where spikes in EKF4.DS of up to 25% of the threshold have occurred.
A value of closer to 10% for normal operation is preferred.
AP_Compass: added COMPASS_PRIMARY parameter

this allows selection of which compass is the primary. Useful if the
first compass starts giving spurious data (as happened in our plane)
HAL_PX4: fixed use of FMU servo pins as digital inputs

these pins can be PWM output or digital input or digital output
Plane: BallDrop initial (mega)commit
APM_Control: deprecate P gains and use FF gains
AP_AHRS_NavEKF: Use EKF for attitude unless states are NAN
NOPUSH(SPLITUP): steer controller acceleraiton limiting, stopping point prediction
APM_Control: Decay integrator over 10 seconds
APM_Control: Base stopping point on desired, rather than measured rate