New features for content acquisition lanes

[leonardr]

To have the functionality of the content server within a circulation manager, we need a way of presenting an OPDS feed that is designed for consumption by another circulation manager. The simplest way to do this is to add some special configuration to a lane.

In brainstorming with Amy we determined these features were necessary for such a lane:

• For a lane not based on a custom list, items are bumped to the front of the lane when their LicensePool is acquired.
• For a lane based on a custom list, items are bumped to the front of the lane when they are added to the list.
• Items are bumped to the front of the lane when their metadata changes.
• Since the URL to the lane may be given out to external parties, it should have a short, reliable URL rather than having a URL that incorporates its internal database ID.

[leonardr]

Doing this for lanes in general was too complicated, so we decided to do it for individual custom lists, as well as collections and libraries. The work is done for custom lists.

[leonardr]

This work is now done for collections and libraries, and the URLs don't include the internal database IDs, so I'm claling this done.