Bugfix: The checkbox in the setting-dialog is not updated.
Bugfix: Default type cannot be set.
Add Relation-Edit-Mode
1. Relations can be created.
2. Relations will hover at Relation-Edit-Mode only.
3. The Edit-Mode transition is below:
   from mdoe: action         : to mode
 1. term:       : instance on  : instance
 2. term:       : relatin on     : relation
 3. instance   : relation on   : relation
 4. instance   : instance off : term
 5. relation    : relation off   : instance
 6. relation    : instance off : term
Edit realation is available!
Save relations.
Add edit actions with the ctrl-key and the shift-key.
Fix edit action for span with the shift-key.
Refactoring bodyClicked.
Set outlook of edit-modes by CSS.
Change cursor.