HP5508A replacement v1.4 - new humidity sensor

Sam Goldwasser made a convincing argument that the current code does not meet the timing requirements for the 1-wire bus. We are therefore either going to lose samples or not going to be able to get humidity data. Therefore, I am switching to a different humidity sensor, the SHT20.

This sensor is I2C compatible, and can be put on the same bus as the BMT180. The updated wiring diagram, then is as follows:

And the corresponding code is available below.

The change is transparent to the GUI.