Plane: use new scheduler load_average() function

this also simplifies the main loop
Copter: use the new scheduler load_average() call

this also simplifies the main loop
Rover: use the new load_average() API
Plane: make it easier to find task numbers
Plane: run TECS 50Hz code when throttle suppressed

this fixes auto-launch detection using TECS
Plane: use a larger serial buffer

this makes higher rate MAVLink possible again
PX4: Adaptations to latest build changes
PX4: Added config file fmuv2 board, not used yet
PX4: Make parameter storage with SDIO of FMUv2 work
HAL_PX4: enable right FMUv2 drivers

ets_airspeed is ok, but mkblctrl driver doesn't build yet
PX4: added px4-v2 targets
PX4: added io-v2 targets
PX4: moved px4io-*.bin to ROMFS

this is more convenient than users having to copy it over
PX4: adapt rc.APM for FMUv1 and FMUv2
HAL_PX4: some GPIO functions are not available on FMUv2 yet
PX4: disable bma180 driver for FMUv1
HAL_PX4: fixed build on FMUv1
PX4: enable airspeed base driver and meas driver

this uses the new airspeed parent driver from Lorenz
AP_Math: added a quick test of floating point location accuracy

just confirming some maths ...
PX4: fixed airspeed build on FMUv1