public Disposable start(final int flags) {
        return start(flags, 0, TimeUnit.SECONDS);
    }
Register the current GeoDirHandler for GeoData and direction information (if the preferences allow it).

@param flags a combination of UPDATE_GEODATA, UPDATE_DIRECTION, UPDATE_GEODIR, and LOW_POWER
@return a disposable which can be used to stop the handler
main/src/main/java/cgeo/geocaching/sensors/GeoDirHandler.java