Add PIOS_SENSORS to all the targets
PiOS L3GD20: Update to the new sensor API.  Remove functions from the public
API that should no longer go there and make others static.
PiOS LSM303: Update to the new sensor API and remove public facing API
that should no longer be exported.
PiOS LSM303: When the data ready semaphore expires then kickstart the
sensor (used to be in the attitude task).
PIOS HMC5883: Make sure the dev struct is not global
PiOS LSM303: Move the configured flag into the device structure.  Make sure the
task doesn't try and run before the device is valid.
PIOS L3GD20: Swap the axis to the standard orientation on the FlyingF3.  This
will need to be confiugrable if someone else uses the L3GD20.
Sensors: To avoid warnins and errors for FlyingF3 allow up to 1 ms
to wait for accel data.  This is because the gyro and accel are not
synchronous on this board.
INSGPS: Add accessor method to get at the internal Nav structure
Makesfiles: Enable  -Wl,--warn-common and  -Wl,--fatal-warnings in all
the makefiles
Sensors: Make some methods static
PIOS HMC5883: Update the initialization on the other targets
CopterControl: Get it working with new PIOS_MPU6000 driver
CopterControl: Convert the old non-CC path to use the common functions for the UAVOS
Calibration: Have to set the updated command to disable gyro bias on the FC side