Representation of a single user.
This class is the container for information about Gallery users.  Each instance of User  contains a unique user id. It must be implemented by a class that has a persistent store for  the relevant user data.
		
			| G2: | <class-name>GalleryUser</class-name> | 
			| Author: | Bharat Mediratta <bharat@menalto.com> | 
			| Version: | $Revision: 17691 $ | 
			| G2: | <parent-class-name>GalleryEntity</parent-class-name> | 
			| G2: | <schema> | 
			| G2: | </schema> | 
			| G2: | <schema-minor>2</schema-minor> | 
			| G2: | <schema-major>1</schema-major> | 
			| G2: | <requires-id/> |