Supposedly the max light brightness is 255, but my Hue and Lightify lights both max at 254. 0 turns off the light, so the range is probably (0, 255) not [0, 255]
The biggest concern is that apparently any device_class with longitude, latitude, and elevation will show up on the HA map (not just device_tracker). In general, however, configuration options in attributes is extraneous and the community voted to remove them (https://community.home-assistant.io/t/circadian-lighting-custom-component/61246/355)
The basis of Circadian Lighting is to figure out how to adjust lights to mimic the sun, which is roughly parabolic above and below the horizon. Originally I used three points to calculate the parabolas - sunrise, sunset, and solar noon/midnight. I did a bunch of generic arithmetic to generate the parabola from those three points. The problem is that this arithmetic generates a parabola from _any_ three points - in reality the points I have are the intercepts and vertex.
The problem with the old method is that if solar noon/midnight did not fall exactly between sunrise and sunset then the calculated vertex could be more or less than 100%, which would cause the integration to set color/brightness values above or below the set min/max. Generating a parabola from the intercepts and vertex is much simpler and also should guarantee the min/max are what's expected.
In addition to this change, I'm also now calculating 4 "half" parabolas instead of just one for above horizon and one for below horizon. The "half" parabolas are: sunrise->solar-noon, solar-noon->sunset, sunset->solar-midnight, solar-midnight->sunrise. This is necessary for the case where solar noon/midnight don't fall exactly half way between sunrise and sunset, which is especially prevalent for users who specify a specific time for sunrise or sunset but not both.
I'm embarrassed at how it's been before it dawned on me that I could calculate the parabolas from intercepts/vertex rather than the three random points method, but hopefully this fixes inconsistencies for users - it should definitely fix issue #25!
astral seems to only be compatible with with deprecated time zone strings, and because times returned are timezone aware the calculations still work properly.
Include time_zone and elevation to get more accurate times. Always pass date into get_sunrise_sunset (otherwise it was returning inconsistent results). Add some debug logging.
