Daylight framework crashes app if the location is inside polar ring.

[imvenj]

Locations inside polar ring, will have polar days (sun never sets) and polar nights (sun never rises).

private func hourAngleOfSunrise(latitude: Float64, solarDeclination: Float64, solarElevation: Float64) throws -> Float64

This function return NAN when sun never rises or sun never sets.

I have made a work around to solve this problem by throw an error from there (and re-throw it along the method chain). I don't have a better solution to handle this situation, so I hope you can look into it.

The workaround I've made was in commit eca031c.

Thank you.