Release v18.09.0

• Change versioning scheme to match USD's new scheme, YY.MM (18.09)
• Add Unity Editor & run-time support for OSX
• New support for several USD features:
  • UsdRelationship serialization support
  • UsdAttribute connection serialization support
  • UsdPreviewSurface, PrimvarReader, TextureReader high-level serialization support
  • Unity StandardShader & Texture2D serialization support
  • UsdSkel bindings
  • UsdShade with high level serialization support (Shader, Material, MaterialBinding)
• New Unity examples for mesh export and material import
• Multiple bug fixes

Release v0.8.5.0

• Updated USD to v0.8.5
• Removed z-lib from Unity Asset Package (no longer required)
• Removed pdb and mdb files from Unity Asset Package
• Updated .NET assembly versions to reflect the SDK version 0.8.5.0

Release v0.8.4.0

• Updated USD to v0.8.4
• Removed initial support for UsdShade (now pending for a future release).
• Removed shading examples.
• Updated .NET assembly versions to reflect the SDK version