Copter: remove unused GPS and baro filters

Saves 24bytes of RAM
Removing the baro filter leads to noisier Baro Alt appearing in the log
so we should make the inertial nav altitude appear in the CTUN message
Copter: rename failsafe to failsafe_radio

Makes way for separation of failsafes for throttle, gps and gcs
Copter: GPS Failsafe implemented

Switches to LAND mode 5 seconds after losing GPS if you're in a flight
mode that requires a GPS
Rover: fixed PX4 MPU6000 driver for rover
HAL_PX4: auto-create APM directory on SD card
InertialNav: remove 3sec limit on position est after losing GPS
Copter: bug fix for auto missions over 320m

get_throttle_althold_with_slew's target_alt parameter defined as int16_t
(instead of int32_t) meaning missions with altitudes >320m could wrap
around and become negative.
Copter: leonard's smoother alt-hold transition

Target altitude when entering alt-hold is based on a projection from
current alt and climb rate
GPS_UBLOX: fixed auto-config of baudrate

this fixes the setting of the baudrate on a uBlox that is configured
for 9600. It fixes the NMEA message to have a \r\n, plus sends the
NAV_SOL rate config before the NMEA baudrate config message.

This fixes issue #159
Copter: fix init of wp_verify_byte so wp alt is always required
Copter: remove unused crosstrack variables and parameters

Cross track is still calculated internally to the wpnav controller so we
should move this to a library and still report it to the ground station
Copter: remove tilt compensation parameter

Note: this idea of feed forward tilt compensation is being incorporated
into the inertial nav based loiter and wp controllers but does not
require a separate tunable parameter
Copter: remove #define for CROSSTRACK_GAIN

Note: the cross track is still calculated inside the inertial nav based
loiter and wp controls but it's no longer requires a tunable parameter
HAL_PX4: workaround problem with APM file on SD card

this works around file redirection bug from earlier firmwares
HAL_AVR: fixed build.Examples in autotest
build: added all 7 copter frame types to binary build
Tools: added the top level scripts for autotest
Tools: build all the PX4 copter frame types
Copter: fix to allow building HIL_MODE_SENSORS
Copter: remove support for CLI Slider