Implement basic BGP routes filtering policies

Basic conditions

• match originator set
• match cluster-id set
• match peer-role set
• community
• ext-community
• as-path set
• med eq
• next-hop-in
• as-path length
• local-pref-eq

Basic actions 

• accept
• reject
• as-path prepend
• set community
• set excommunity
• set originator-id
• originator-id prepend
• cluster-id prepend
• set local-pref
• set next-hop
• set med
• transitive attributes filtering