iOS SDK v.5.4.1

• added the blUserLocale property (two character code) to the BackendlessUser object
• added methods to UserService:

- (void)setUserToken:(NSString *)userToken;

-(NSString *)getUserToken;

-(BackendlessUser *)loginAsGuest;

-(BackendlessUser *)loginAsGuestWithStayLoggedIn:(BOOL)stayLoggedIn;

-(void)loginAsGuest:(void(^)(BackendlessUser *))responseBlock error:(void(^)(Fault *))errorBlock;

-(void)loginAsGuestWithStayLoggedIn:(BOOL)stayLoggedIn response:(void(^)(BackendlessUser *))responseBlock error:(void(^)(Fault *))errorBlock;