-(AlfrescoRequest *)
                retrieveFavoriteSitesWithCompletionBlock:(AlfrescoArrayCompletionBlock)completionBlock
            - retrieves a list of sites in the repository that the current user has explicit
            membership of and which have been marked as a favorite.
        Parameters
- (AlfrescoArrayCompletionBlock) completionBlock
 - The block that is called with the sites on completion of the operation. The format of this block is typedef void (^AlfrescoArrayCompletionBlock)(NSArray *array, NSError *error).
 
Returns
(AlfrescoRequest *)
Example