Minor
Don't allow validation dialog to grow too tall

Also:

- remove unneeded hints
- update itemset dialog CSS
Minor: don't use ev:*
Validation dialog: wider column for French
For #794: warnings review dialog

- processes
  - new suspend/resume/abort actions
  - new warnings action to check warnings
  - new dialog action to show a dialog
  - update processes to check for warnings when needed
- add warnings review dialog
- add instance to save process continuation