Remove the delegator module, introduce the page manager module. Anything that previously relied on delegator module must now change its code to rely on page manager instead!

Allow restricting contexts via access control to allow the add content UI to remove irrelevant content.

Make access plugins a little less focused on the term "access" and change selection criteria to selection rules.

Implement titles; this caused a retooling of the return value of the context task handler rendering so be sure to sync up.

Retool the access plugins to allow multiple plugins plus and/or switch. Retool selection criteria to use this allowing for a much richer selection of task handlers on a given page.

Checkpoint checkin. Lots more interesting functionality -- pages can now be set to "single" or "multiple" task handlers, and having "single" removes the task handler arrange UI. Please some serious code re-organization so that Panels can have just one context-based task handler for multiple tasks.