rose documentation: implement feedback
rose edit: revert page now reverts errors
rose edit: also revert warnings
Merge pull request #600 from benfitzpatrick/rose-edit.revert-page-change-errors

rose edit: revert page now reverts errors
rose documentation: implement review feedback
Merge pull request #599 from benfitzpatrick/doc.feedback-training

rose documentation: implement feedback
Merge branch 'master' of github.com:metomi/rose into metomi-gh-pages