Fix some bugs Flump5281 helped point out.
Add origins to items, also some bugfixes.

Items now contain an optional URL stating their origin, if the driver provides
that information.  See API_CHANGE_LOG for details.
Move duration to Items.

This removes the duration variable from the Player, also.

In addition, Items now forward attempts to driver_put into them to their
parents as driver_posts.

API version bumped to 0.3.0.
Update API changelog.
Attempt to implement in-request WS auth.

This needs testing.
Add request to update changelog.