Allow LuaSurface.evening to be > LuaSurface.morning

[Mylon]

surface.dusk can be < 0 and surface.morning > 1, creating a situation where minimum surface.darkness > 0, but evening cannot be > morning, preventing a situation with maximum surface.darkness.

I'm creating a seasons mod that adds varying day lengths. With the current logic, I cannot support an Arctic circle summer.

[Tekky]

I believe that this thread belongs in the "Modding Interface Requests" sub-forum instead of the "Ideas and Suggestions" sub-forum.