FIXME: Only include attributes that are defined in portlet.xml
This is a default implementation of that gets user information attributes
from a properties file where the user information attribute name (as defined
in PLT.D of the JSR-168 spec) is prefixed by the user name (e.g. craig.user.name.given=Craig).
Implementation of PLT.17.2 used to access user information attributes.
See Also:UserInfoAttributesService.getUserInfo(javax.portlet.PortletRequest) As per the spec, return null if the user is not authenticated or an empty Map if there areno attributes in the properties file or a Map containing only those attributes found in the attributedata store (properties file).