The default behaviour is unchanged, but if you write "yes" to
$:/UploadWithUrlOnly then it will assume it's possible to upload
with a blank username and password, as long as the host is set.
The motivation is to support a upload plugin compatible upload
service that uses some method to authenticate other than the legacy
upload plugin user/password params.
Without this patch, the user would need to enter something random in
the user and password fields for TW to decide the upload plugin can
be used.
Causes the wiki to be autosaved whenever clicking “done” after editing
a tiddler. Only works with savers that support autosave. We should
probably make autosave configurable
We were re-using the `tw-save-wiki` message both for saving the current
wiki and downloading a new wiki. Now we’ll use the separate
`tw-download-file` message for downloading.
Fixes#236
