Switch from CityID to Lat an Lon, expose sunrise and sunset

[Sudrien]

#232 mentions settings.gmtOffset should not be seconds, but it sure looks like it's seconds in the examples.

It also mentions OpenWeatherMap API changes. This

• updates the API call (less concat, more replace)
• exposes settings.lat, settings.lon, settings.sunrise, settings.sunset for more options
• updates the samples