FB Release v2020.06.29.01 + BigSur compatibility patch
This includes:
- all commits from FaceBuck through the 2020.06.29.01 release
- all commits from Addepar's fork played on top of the 2020.06.29.91 release
- a special cherry-pick of facebook@a2912b9 with merge conflict resolution, to support Big Sur.
- a specific delete of python interpreter change to retrofit to python 2.7
SHA1: b92f7140341007ff40f79ad65118f1b4e05e23f6