Temporary files are not deleted when using multipart requests

The multipart provider uses mime4j to parse multipart messages. To store the messages it initializes a TempFileStorageProvider which stores the messages as temporary files on the harddrive. Unfortunately these files are only deleted, when the JVM exits, the internal delete() method doesn't seem to be called from RESTEasy. When processing lots of requests with a lot of data the temporary files need a huge amount of storage until Tomcat restarts.