Merge "Improve documentation of getAltitude" into gingerbread

     * Typically the atmospheric pressure is read from a

     * {@link Sensor#TYPE_PRESSURE} sensor. The pressure at sea level must be

     * known, usually it can be retrieved from airport databases in the

     * vicinity.

     * vicinity. If unknown, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE}

     * as an approximation, but absolute altitudes won't be accurate.

     * </p>

     * <p>

     * To calculate altitude differences, you must calculate the difference

     * between the altitudes at both points. If you don't know the altitude

     * as sea level, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} instead,

     * which will give good results considering the range of pressure typically

     * involved.

     * </p>

     * <p>

     * <code><ul>

     *  float altitude_difference =

     *      getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2)

     *      - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1);

     * </ul></code>

     * </p>

     *

     * @param p0 pressure at sea level