* Implement ASPageTable
- It is a screen page table that can be used to quickly filter out objects in a certain rect without checking each and every one of them.
- ASCollectionLayoutState generates and keeps a table that maps page to layout attributes within that page.
- ASCollectionLayout (and later, ASCollectionGalleryLayoutDelegate) consults its layout state for `layoutAttributesForElementsInRect:`. This ensures the method can return as quickly as possible, especially on a large data set (I heard some people have galleries with thousands of photos!).
* Address comments
* Handle items that span multiple pages
* Make danger happy
* Make ASCellNode indexPath and supplementaryElementKind atomic
* Update the change log
* Fix licenses
* Be explicit with atomic
* Rename the protocol
* And the file
* [Yoga Beta] Improvements to the experimental support for Yoga layout.
Yoga remains an unsupported / speculative feature, but these improvements are important for
the functionality of clients that are experimenting with it.
For example, without these changes, ASButtonNode is not able to lay out correctly. These
changes allow certain subtrees that use layout specs to coexist properly in a Yoga heirarchy.
The most significant change here is moving ASEdgeInsets into the #if YOGA gating. Although
this is technically an API change, this type was added with no known use cases and is
really only useful for flexbox layout specification. So, before usages of it are created,
it makes sense to constrain the Texture API surface until that time.
* [RTL] Bridge the UISemanticContentAttribute property for more convenient RTL support.
Although apps could handle this before by setting the view's property in didLoad, it's
useful to bridge this property for setting during off-main initialization.
This change also makes RTL fully functional / automatic for Yoga layout users.
* Remove RTL property addition and depend on PR #60 landing first.
* Fix warnings
* Add line to changelog
* Fixes a potential deadlock; it's not safe to message likely super nodes while holding the lock.
* I think this is what @nguyenhuy is looking for :)
* Fix up CHANGELOG.md