Selective route refresh for BGP

This document proposes a new Route Refresh mechanism which provides ability to perform route refresh for a smaller subset of updates than the entire Adj-RIB-Out. It is applicable to multiple deployment scenarios like , BGP-LS [I-D.draft-ietf-idr-ls-distribution-11] , EVPN [RFC7432]. The suggested capability will help faster convergence and minimize overhead for routing policy changes. This document updates [RFC7313].