Supported the postMessage-style new metadata format.
Resolved issues
Updated to the current structure used in backend-update-center2.
This incorporates fixes for IE and correct character encoding handling
JDK 5 compatibility.
Linked to online documentation.
Known issues
CloudBees Internal Ticket: RM-1556
If a custom update center defines no core (jenkins.war), it is
impossible to connect to it from a downstream controller running Jenkins
1.483 or later.
CloudBees Internal Ticket: RM-1554
Update centers must be readable by anonymous user to function.