code: public ExtendedRelation addRelationship(String baseTableName,
  			String relatedTableName, String mappingTableName,
  			String relationAuthor, String relationName) {
  		return addRelationship(baseTableName, relatedTableName,
  				mappingTableName,
  				buildRelationName(relationAuthor, relationName));
  	}
docs: Adds a relationship between the base and related table. Creates a default
  user mapping table if needed.
  
  @param baseTableName
  base table name
  @param relatedTableName
  related table name
  @param mappingTableName
  mapping table name
  @param relationAuthor
  relation author
  @param relationName
  relation name
  @return The relationship that was added