Added Android sensors to android_gingerbread_mr1.

Add new sensors (code used to live in Android Sensors Driver).  Also updated Orientation publisher.

In the next few days, I'll be adding the sensors that have appeared in later Android API versions like TYPE_AMBIENT_TEMPERATURE, the new Fused Location API, and maybe even the uncalibrated gyro and magnetometer types.

Since these are new files (and one minor change), should be fine to merge into hydro branch and not wait for indigo.  @damonkohler @stonier, if we think the changes to OrientationPublisher are too great, we can hold off on that one and merge the rest.