* Add move detection and support to ASLayoutTransition
...and NSArray+Diffing.
Add some tests.
* Update CHANGELOG.md
* Update CHANGELOG.md
* Update ASLayout+IGListKit.h
* Update ASLayout+IGListKit.mm
* Use std collections to avoid NSNumber boxing
* Update ASLayoutTransition.mm
* Code review updates.
* Use `unordered_multimap` on stack instead of unordered_map<id,queue> on heap
* Remove notFound BOOL (use NSNotFound sentinel value) and put some vars inside the if (insertions/moves) loop
* Don't copy defaultCompare block (redundant under ARC)
* Whitespace
* Remove unneeded mutableCopy-s in ArrayDiffingTests
* Code review updates.
* Type _subnodeMoves pair.first to ASDisplayNode * instead of id
* C++ enumeration
* unowned refs for adding previousLayout nodes to _subnodeMoves
* Remove unreleated ASDynamicCast that is probably right though
* Add commentary to NSArray+Diffing.h; make multimap elements unowned
* Use std::make_pair, optimize ASLayout+IGListKit
* Oops I thought I had added these headers but nope
* Simplify simplify
* Diff subnodes instead of sublayouts
* Another randomized test with actual ASLayouts
