Generic iuse function for weather reading devices

I changed the iuse function that read weather to be more generic. If an item is flagged and has the action "weather_reader", it will read the weather. For example, when thermometers are added, it will only have the one flag and thus only display that one piece of information, but still use the same generic function! yay!
Pressure is normally display in kPa, but the weather generator uses kPa*10. I decided to move the /10 into the print function, but I can understand if that was a bad idea and should instead divide it before sending it to the print function.

Should I change it or keep it?