xlint 0.2.2

Lint engine for x
docs.rs failed to build xlint-0.2.2
Please check the build logs for more information.
See Builds for ideas on how to fix a failed build, or Metadata for how to configure docs.rs builds.
If you believe this is docs.rs' fault, open an issue.

Lint engine.

The overall design is generally inspired by Arcanist's lint engine.