Improve sun controls

It would be helpful, if the sun altitude slider went to 180° ie.: from dawn till dusk.
If the azimuth is say X, when the altitude is greater than 90°, say Y, the altitude would then be considered to be 90°-Y, and the azmith would be X+180° mod 360°.

This way you could play with the sun slider in a slightly more intuitive manner.