Baro_BMP085: use healthy flag
Baro_HIL: use healthy flag
Baro_MS5611: use healthy flag
Baro_VRBrain: use healthy flag
Baro_PX4: use healthy flag
Baro: example sketch to use healthy() function
Arming: use baro healthy() function
BaroGlitch: use baro healthy()
Copter: use baro healthy()
Plane: use baro healthy()

Use baro last update time in place of healthy to determine whether HIL
sensor updates have started
Baro: init members to resolve compiler warning
BaroGlitch: check baro health after alt calculation

Also correct type of distance_cm internal variable
Copter: increase sonar timeout to 1sec

Contributed by Julien Dubois.
Antenna: move up one directory
Tools: update build script for Antenna move
Antenna: update makefile for new location
AutoTest: update sim_vehicle for antenna move
Tools: build antenna tracker for firmware.diydrones.com
Copter: bug fix to rally point alt

rally point library uses absolute altitudes, we were passing in relative
altitudes which caused the vehicle to climb before heading to the rally
point
Rally: fix comment to clarify altitudes are absolute