Bugfix SUP-1126
When deleting text after a non-editable element the cursor could
disappear in some browsers, which prevented further editing. This
has been fixed.
Bugfix SUP-1147
The behavior when pressing DELETE before a table or BACKSPACE after a table
was inconsistent and unexpected. Sometimes the whole table was deleted, sometimes
the selection moved into the first/last table cell.
This has been changed now to be consistent and conservative: When pressing DELETE before
or BACKSPACE after a table, the selection will stay where it was and nothing will be deleted.