Minor Errors - Weather Station

I have discovered a few errors in the Weather Station description.

1. The Weather Station DSA is 80, not 133 as described in Table 257.

2. In WEATHER_STATUS_1, Relative Humidity should be a single byte value. Thus, Byte 6 should be Relative Humidity, Percent, per Table 4. Byte 7 should be reserved.

3. In section 530.4, third paragraph, "or a Compensated Pressure of 980 and a Altitude Basis of 980 (sea level)", should read "or a Compensated Pressure of 980 and a Altitude Basis of 1013 (sea level)".