AP_HAL: removed separate Console class

the idea of a separate console class was never really used, and just
added confusion in a HAL port. It also consumes some much needed ram
and flash space on APM2
HAL_AVR: removed Console driver
AVR_SITL: removed Console driver
HAL_Empty: removed Console driver
HAL_FLYMAPLE: removed Console driver
HAL_Linux: removed Console driver
HAL_PX4: removed Console driver
AP_Baro: added update_calibration() method

used for auto baro calibration when disarmed
Plane: auto-update home and baro calibration when disarmed

this takes advantage of the PX4 arming state to ensure position and
baro calibration is updated
Copter: simple mode speedup

super simple and simple mode headings separated
g.super_simple converted into a bitmap by flight mode switch position
AutoTest: add super simple test
HAL_AVR: fixed examples build
HAL_FLYMAPLE: removed unused backend console code
Plane: use a rally point when out of mission items
Copter: add safe switch arming check
AutoTest: remove LAND from end of copter mission
AutoTest: shorten simple and super simple tests
Plane: added RALLY_LIMIT_KM

this will prevent an embarressing use of a rally point from the wrong
airfield
Plane: honor zero RALLY_LIMIT_KM
Merge remote-tracking branch 'upstream/master'