BUG #15121: Expose Ambient/Diffuse components.

Ambient/Diffuse factors are now exposed on the Properties panel. Create
a Sphere and search for ambient/diffuse in the properties panel to see
these. These properties are "advanced" by default.

Change-Id: I09320a31715f383555c773c2f6aa8bef6d2c5b98
Merge topic '0015121_fix_ambient_diffuse' into next

bdd22c31 BUG #15121: Expose Ambient/Diffuse components.