Fixed several problems with the Sun: some settings didn't work, or were inconsistently used. - The sun position is always calculated by combining the sun settings in the Region and Estate. This fixes the problem that 'UseEstateSun' didn't work. - To remove ambiguity, the EstateToolsSunUpdate event no longer accepts the sun's position as parameters. That's because the position is always calculated from the Region and Estate settings. - Use only the 'FixedSun' flag to determine whether the sun is fixed; not the 'UseGlobalTime' flag. - Don't change the region's 'SunPosition' field according to the sun's position: this field is used only to set the position when using a FixedSun. (The 'SunVector' field does get updated according to the sun's position in the sky)