Summary:
Ref T9994.
- Allow errors to be dismissed.
- Tailor messaging for closed/abandoned revisions.
- Reduce scare messaging on land dialog, since it's not really that scary anymore.
Test Plan:
- Dismissed errors.
- Hit new warnings.
- Wasn't as scared when landing.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T9994
Differential Revision: https://secure.phabricator.com/D14886
