in appleseed.studio, allow binding a color to the alpha map input of a material.
fixed double contribution of the lighting from the environment on glossy materials when IBL is enabled, in PT and DRT lighting engines.
cleaned up test suite: environment.
cleaned up test suite: ewa.
exclude invalid scenes from test suite.
cleaned up test suite: lights.
exclude minimal test suite.
cleaned up test suite: missing material.
cleaned up test suite: multiple importance sampling.
cleaned up test suite: negative scale.
cleaned up test suite: normal modifiers.
cleaned up test suite: missing intersections.
cleaned up test suite: self intersections.
cleaned up test suite: obj.
cleaned up test suite: per-face materials.
cleaned up test suite: reconstruction filters.
cleaned up test suite: scattering modes.
added back the approximate RGB-to-spectrum conversion code to easily match old renders when debugging.
removed "spectral" from the color space combo on textures.