BUG: TexturedSphereSource bad texture coordinates

In 2012, an attempt to replace vtkMath::TwoPi() with 2.0*vtkMath::Pi()
was incorrect. After further investigation, the offending committer
was Bill Lorensen. Shame on you!

Filters/Hybrid/Testing/Data/Baseline/earth_1.png.md5

-2261e0605d932a50421f60bc7895bec7

Filters/Sources/vtkTexturedSphereSource.cxx

@@ -102,7 +102,7 @@ int vtkTexturedSphereSource::RequestData(
   for (i=0; i <= this->ThetaResolution; i++)
   {
     theta = i * deltaTheta;
-    tc[0] = 2.0 * theta/vtkMath::Pi();
+    tc[0] = theta/(2.0 * vtkMath::Pi());
     for (j=0; j <= this->PhiResolution; j++)
     {
       phi = j * deltaPhi;

Rendering/Core/Testing/Data/Baseline/TestOpacity2.png.md5

-969c1b03d4d4a450f61ea3897caf9dd4
+f4053792345cb46d0a6f2d39b3e5767f

Rendering/Core/Testing/Data/Baseline/TestOpacity2_2.png.md5

-1b77aface6652194cd699260a1e4c861
+1fbb7381bc8fadfb84bb98c8242de444