Add support for a completely customized sequence of (time-point, brightness, temp) tuples and let the AL engine adjust between when active

[nu]

Since this addon is so advanced, I was surprised this mode doesn't exist.
This would allow the ultimate control.
Some extra optional properties of this new feature:

• allow time-point to be either an timestamp or an offset from the two special points of Sunrise and Sunset
• allow choice of interpolation method between each point in the sequence

In fact, if you implement the above ones as well, this would allow you to then restate the existing "default", "linear", "tanh" as simple presets implemented on top of this new generic feature.

This would lead to both some simplification but at the same time ultimate power for people to do their own thing.

This will also subsume the need to do special things like 'asymmetric' treatment of Sunrise and Sunset which is already a feature request. :)

Let me know if you have any questions. Thanks!