Xiang Zhang authored Jun 10, 2019 and David Flynn committed Nov 21, 2019

This adoption permits coding geometry with non-cubic bounding boxes.
Since the depth of the tree remains constant for cubic and non-cubic
bounding boxes with identical largest dimensions, quad-tree and
binary-tree partitions are introduced to avoid coding 'fractional'
positions.

The following configuration options control the placement of non-octree
partitions within the coding tree:

 --max_num_implicit_qtbt_before_ot
 --min_implicit_qtbt_size_log2