Merge edits.
Remember which control was clicked.

When a submit control is clicked, remember its name, so that the click
can be replayed after validation. This ensures that the control is
included in the form submission.
Allow aborting deletion in onDelete event.

See issue #151 and #224.
Merge branch 'github-main' of github.com:plomino/Plomino into github-main

Conflicts:
	Products/CMFPlomino/PlominoDocument.py
Tweak widget descriptions.
Reorder imports.
Merge pull request #227 from plomino/jean-220-submit-control

Remember which control was clicked.
Merge pull request #228 from plomino/jean-151-onDelete-abort

Allow aborting deletion in onDelete event.
merge