* Added a bunch of unit tests and added text input to uikit feature
* cargo fmt
* I dunno what this is but it wasnt checked in
* Fix uikit unit tests
* maybe fix cargo fmt
* Fix iOS run
* fix cargo fmt
* Maybe fix cargo fmt
* maybe fix cargo fmt
* cargo fmt
* Try to fix cargo fmt one more time
* cargo fmt
- Changes internal target_os flags to be feature flags; macOS is now
appkit, and iOS/tvOS are now uikit. This enables platforms that are
not Apple-specific platforms that use frameworks to be compiled for.
- Updates the examples to handle closing/quitting better.
- Corrects `feature` -> `target_os` checks.
- Updates the old iOS scene delegate pieces to use the new class
structure.
- Bundles in an iOS demo app.
- Blocks off most things that should not even attempt to compile for
iOS.
