#4093 and #4100 are bundled in this PR
* qualified state-tiddlers for the tags input and fieldname + fieldvalue inputs
* newTagName, newFieldNameTiddler and newFieldValueTiddler variables defined in EditTemplate (all qualified through `qualify` macro)
* save-tiddler-actions macro in the EditTemplate (reused by the save-tiddler button)
* enter (configurable) in the fieldvalue field adds the field and sets focus to the next fieldname input
Edit:
* storyview="pop" for fields list
* Minor rewording of prompt text
* Moved the colon into the translation string, reasoning that it may need to be changed for languages that use punctuation differently
* Corrected expand/collapse arrows
* Moved prompt into expand/collapse button, making it easier to hit use
* 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
* fr-FR translation of additional error strings
* include SaveTrail
* Amendments to the warnings upon loading content via _canonical_uri
* Typo: add a missing THE
* Clarification on why the browser might refuse to load external content
When renaming an existing tiddler, the edit template now shows a
checkbox that determines whether or not to relink references to the
tiddler in the list or tags fields of other tiddlers.
A bunch of little changes that together enable external image support.
Try:
```
tiddlywiki editions/tw5.com --verbose --build externalimages
```
Then open `externalimages.html`, look for the images in the more/types
tab of the sidebar, open them and verify that they are set with an
external SRC attribute, not a data URI.
1. Moved some methods out of boot.js because they are not needed until
after bootup
2. Added alternate message for editing an overridden shadow tiddler
3. Minor style tweaks
