* [Yoga] Rewrite YOGA_TREE_CONTIGUOUS mode with support for mixing with ASLayoutSpec.
After experimentation with the ASYogaLayoutSpec (or non-contiguous) approach to
integrating Yoga, test results and feedback from the authors of Yoga have shown
that this approach can't be made completely correct,
There are issues with some of the features required to represent Web-style
flexbox; in particular: padding, margins, and border handling have varience.
This diff is a first step towards a truly correct and elegant implementation of
Yoga integration with Texture. In addition to reducing the footprint of
the integration, which is an explicit goal of work at this stage, these changes
already support improved behavior - including mixing between ASLayoutSpecs
even as subnodes of Yoga layout-driven nodes, in addition to above them. Yoga
may be used for any set of nodes.
Because Yoga usage is limited at this time, it's safe to merge this diff and
further improvements will be refinements in this direction.
* [ASDKgram] Add Yoga layout implementation for PhotoCellNode.
* [Yoga] Final fixes for the upgraded implementation of the Contiguous layout mode.
* [Yoga] Add CHANGELOG.md entry and fix for Yoga rounding to screen scale.
* [Yoga] Minor cleanup to remove old comments and generalize utility methods.
* Reimplement IGListKit support in a cleaner way
* Rename and fix some stuff
* Fix supplementaries more
* Update docs
* Update test
* Cleanup minor things
* Tweak it
* Indentation
* Remove irrelevant changes
* Break out cell into its own file
* Fix indentation
* Address feedback
