Mapping from conditionCode to symbol file

[drmrbrewer]

Just curious, @hrbrmstr, where do you map from a particular conditionCode (e.g. "HeavyRain") to an actual symbol file (e.g. "wi-day-rain.svg")? It isn't a one-to-one correspondence (i.e. you can't just choose a file called HeavyRain.svg because it doesn't exist), but I can't see that mapping anywhere? I can see a wx_icons_path function in here, but it doesn't seem to do any actual mapping as I would expect :-/