Auto Correct High Degree Confidence Corrections

**What problem does this solve?**
During a Q&A at WordCamp this was mentioned. If harper has a high degree of confidence in an issue it should just make that correction automatically.

No file, test, or entry point is named in the issue. First clarify what qualifies as high confidence, which corrections may be applied automatically, and how users can review or undo them; done means those rules are implemented and high-confidence corrections occur automatically.

Written by the indexing model from the issue text.