Add table widget
Implement table editor drawing
Store table content state in element data
Implement delete-column button
Implement delete-row button
Simplify delete-row logic
Implement add-row button
Implement add-column button
Use tbody and tfoot elements as well as thead
Mark control elements consistently
Read table contents before restructuring
Don't need to explicitly set object property to undefined
Store table contents on widget save
Restore table content on edit
Set up default table structure on new widget creation
Implement table widget rendering
Select link with explicit link class
Add function comments
Add edit-link icon
Add url-editor modal