A recent change added a request parameter to SiteSettingsForm, and

changed the calls in siteconfig to pass the data and files

values as keyword arguments.
This broke the form, because extensions use the configure_extension

view, which passes data as positional arguments.
While that view could also just be updated for this, the convention is

to pass data and files as positional arguments, and most callers do

so. To provide the best compatibility, we now do this as well, and leave

optional keyword arguments (request) as keyword arguments accessed

through kwargs.

Successfully saved extension settings.
Unit tests pass.