* [ASEnvironmentTraitCollection] default user interface idiom to ASEnvironmentTraitCollection
UIUserInterfaceIdiomUnspecified is -1 so we were actually defaulting our trait collection to UIUserInterfaceIdiomPhone (which is 0).
* Fix a few places where we weren’t using the default method to create the base traits
Passing around a pointer was leading to crashes as the ASVC was the sole owner of the context. There are cases where the VC would dealloc while its subnodes were laying out. This could lead to the subnodes accessing a garbage pointer.
* Perhaps controversially, decomposing ASRangeControllerUpdateRangeProtocol+Beta.h such that the categories on various classes are defined in the classes themselves since that's where the implementation of those categories is provided.
* Updating unit tests and import other headers the tests took for granted. The tests could probably import the umbrella header and not have to worry about this.
* Updating the "Life without Cocoapods" sample to build and run dependent on ASDK as a static library.
* Added a "Life With Frameworks" sample app to build and run dependent on ASDK as a framework, proving the framework targets work.
* make variable naming reflect ASEnvironmentTraitCollection vs ASTraitCollection
* move trait propagation to cell allocation instead of via a nested block
* move trait propagation when setting a displaynode's supernode instead of when adding a subnode
* fixed misspelling of "colection"
Initial attempt to get display traits working with ASEnvironment.
To get proper ASDisplayTraits support, you must use an ASViewController. The ASViewController implements UITraitCollection-related methods (`traitCollectionDidChange:`, `willTransitionToTraitCollection:withTransitionCoordinator:`, viewWillTransitionToSize:withTransitionCoordinator`) to update the internal ASDisplayTraits and propagate them to subnodes.
ASTableNode and ASCollectionNode don't actually have their cells as subnodes, so a little bit of trickery is involved (on `setEnvironment:` the table/collection node gets its data controllers completedNodes and propagates the new traits. see `ASDisplayTraitsCollectionTableSetEnvironmentState`). The data controller also passes the current display traits when creating new cells.
ASViewController also supports the ability to return a custom set of display traits. So if you have a modal dialog that should always be told it is in a compact size class, you can set the override block before displaying the VC.
A new example, called Display Traits, has been added. It shows how display traits can be used in a ASViewController with a normal ASDisplayNode as its root, as well as in ASViewControllers hosting table nodes and collection nodes. There is also an example of overriding the default display traits of a VC.
Please provide feedback!
