Fix for Proxy URL parameter vulnerability for 13.09

Fix for a vulnerability where client could access localhost resources via proxy url.

Added a permissions file so that the urls that are permitted to be proxied can be controlled.  By default all accesses to localhost (server localhost) are denied.

Also any protected services (extractorapp, geonetwork, etc...) are denied because they must be accessed using the path proxy strategy this way the spring security can add extra authorization checks.
I cannot get the point of using a classloader here, what is the purpose ?