An improvement to 6fb992690d
By making sure that all the popup state tiddlers have the prefix
$:/state/popup/ we can be more selective and just exclude popup state
tiddlers when we save. The end result is that once again other kinds of
state are persisted as expected (eg tabs, and sidebar visibility).
We’re also reverting to the old custom dropdown. Using the select
widget didn’t work out because it couldn’t cleanly work with a text box
allowing custom types to be specified.
By rearranging the `[all[]]` operator we are able to ensure that shadow
tiddlers get processed before ordinary tiddlers. This makes it easier
to create custom stylesheets that override the core.
