Memory leak caused by endless piling up of delete-on-exit hooks for JMX authentication challenges

We're running 7.1.1, with a patch applied for REMJMX-45 to limit the worst leaks coming from the JMX subsystem.

However, even with this patch applied we can only survive for a few days in a production-like scenario.

Inspection of the out-of-memory heap dumps shows a large accumulation of entries inside java.io.DeleteOnExitHook, all having values like "C:\jars\jboss-as-7.1.1.Final\standalone\tmp\auth\challenge-4303257".

Given sufficient JMX connections made to a running instance of 7.1.1, this will at some point exhaust the JVM heap. Typically the paths will be longer than the example above, accelerating the process.