🎉 3.0.0 (TextureGroup#1883)

I forgot this in the last PR and I'm pushing to master, I'm a bad per…

…son.

Prepare for 3.0.0-rc.1 release

Cleanup from recent changes (TextureGroup#1647)

- Fix availability warnings for usage of userInterfaceLevel
- Deprecate `asyncTraitCollectionDidChange` in favor of the new method
- Remove old compiler warning flag added for Xcode 9 building
- Access `textColorFollowsTintColor` with a locked scope

ASSignpost: Add support for the os_signpost API, fixes (TextureGroup#…

…1501)

* ASSignpost: Add support for the os_signpost API

- Removes support for colored intervals. These weren't really useful and they aren't part of the signpost api.
- Fixes an issue with range controller interval logging.
- Adds an interval for interface orientation changes.

* Rename

* Support Xcode 9

* Commentary

Cut version 2.8.1

Correct attributes lookup for supplementary elements. (TextureGroup#1318

)

Correct attributes lookup for supplementary elements. (TextureGroup#1318

)

[Updated Snapshots] Don't add extraneous truncation token during kCTL…

…ineTruncationMiddle (TextureGroup#1375)

* Don't add extraneous truncation token during kCTLineTruncationMiddle

* Expand these comments a little.

* Update snapshot tests with beautiful correct behavior