Distributed Fault Detection Using Relative Information in Linear Multi-Agent Networks★★The Work from Daniel Silvestre Was Supported by the Project Fct [Uid/Eea/50009/2013] and with Grant Sfrh//Bd/71206/2010, from Fundação Para a Ciência e a Tecnologia. J. Hespanha Was Supported by the U.s. Army Research Laboratory and the U.s. Army Research Office Under Grants No. W911Nf-09-1-0553 and W911Nf-09-D-0001. C. Silvestre Was Supported by Project Myrg117(Y1-L3)-Fst12-Mkm of the University of Macau.