• Added EMBREE_COMPACT_POLYS CMake option which enables double indexed triangle and quad
  leaves to reduce memory consumption in compact mode by an additional 40% at about
  15% performance impact. This new mode is disabled by default.
• Compile fix for oneTBB 2021.1-beta05
• Releases upgrade to TBB 2020.2
• Compile fix for ISPC v1.13.0
• Adding RPATH to libembree.so in releases
• Increased required CMake version to 3.1.0
• Made instID member for array of pointers ray stream layout optional again.