* List backlinks when renaming tiddler
* List references inplace
* TiddlerInfo/References accepting specific tiddler
If `operandTitle` is set, it will show its references instead of current
tiddler's.
It's purpose is to prevent code duplication (the references are listed
when renaming tiddler).
* Don't use variable for References template, use <$tiddler>
Set the `current` to desired title with `<$tiddler>` widget.
* List references in a separate block
* Rename state tiddler
* Use qualified state