Add support for Quantec boards in GCS

GCS now recognises the Quantec PID/VID, there is no need to pose as
CopterControl anymore. Uploader support might not work 100% yet, working
on it.
PIOS Sensors: Create a general sensors interface
Update Quantec.pluginspec

Updated Quantec plugin file which I missed in last commit
Sensors: get freedom using the new sensor queues for mpu6000
PiOS HMC5883: Create a task to get the mag data.  This is because these
methods should not be called from userspace
Sensors: Reenable mag calibration
Merge branch 'next' of ssh://github.com/lilvinz/PhoenixPilot into next
Merge branch 'next' of ssh://github.com/PhoenixPilot/PhoenixPilot into next
Merge branch 'next' into general_sensors

Conflicts:
	flight/Modules/Sensors/sensors.c
Sensors: Get MS5611 registering against the general sensor interface
PIOS MPU6000: Changes to the startup code
PiOS MS5611: Make the device handle static
PiOS MS5611: Now the driver doesn't export the GetTemperature / GetPressure
methods they aren't required since they just add more checks on the device
handle for no reason
PIOS MPU6000: Move the configured flag into the device structure
Add PIOS_SENSORS to all the targets
Merge branch 'next' of ssh://github.com/PhoenixPilot/PhoenixPilot into next
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