Patch Set 4: I would prefer that you didn't submit this

tried the following scenario:
- do some change
- stage it
- commit
- repeat that
- do another change and stage it
- click amend, this populates the commit message with the wrong message
- it seems you need to change focus to another repository to fix this wrong transient state

I think we should also store the commit message per repository to enable the scenario to start editing a commit message for a repo, switch focus to another repository do the same there and go back without losing the started commit message. Same for the checkbox states.