v4.2.0

• Add emissive material support
• Add bloom post-processing
• MolViewSpec extension: loadMVS supports keepCamera parameter
• Return StateTransform selectors from measurements API (addDistance, addAngle, etc.)
• Refactor transparency rendering
  • More uniform behavior for blended, wboit, dpoit
  • Fix issues with text & image geometry
• Fix render-spheres example (#1100)
  • Wrong step size in sphere geometry boundingSphere & groupmapping
  • Handle empty instanceGrid in renderer & renderable
• Fix bond assignment from IndexPairBonds
  • Can not always be cached in ElementSetIntraBondCache
  • Wrong operator checks in findPairBonds
• Fix SSAO artifacts (@corredD, #1082)
• Fix bumpiness artifacts (#1107, #1084)