Add Gyroscope sensor userspace driver

Based on the hardware/invensense/libsensors/ example

Requires:
http://review.cyanogenmod.org/#/c/29733/

Change-Id: Idafa069182d60b1be02d018cd208c9e18ac7c853

Conflicts:

	libsensors/MPLSensor.cpp
	libsensors/nusensors.cpp
Continues cleanup