Now we reserve the `title` class for the tiddler title span itself, and
`titlebar` for the previous purpose of identifying the div containing
the title and the toolbar buttons
Belatedly realised that the design would be clearer without these two
separate concepts being conflated into a single widget.
As a result of this change, any other widget or template that generates
transclude widgets has needed adjustment.
Now the ViewTemplate just renders the current tiddler through each
template tagged `$:/tags/ViewTemplate`. This allows plugins (and users)
to add/remove elements from the ViewTemplate easily, without
overwriting the ViewTemplate itself.
(For @giffmex)