RoleFilterTransformer and authentication-fw

[Yannick Menager]

I've been looking at using RoleFilterTransformer with authentication 
framework, but since RoleFilterTransformer uses request.isUserInRole(), 
it won't work with authentication-fw ( unless I've missed something ;) )

That could be fixed by adding a javax.servlet.Filter, with support for 
authentication-fw to it... Should i do it and submit a patch, or is 
there any objections ?