More fullnode -> validator renaming (#4414)

* s/fullnode_config/validator_config/g

* s/FullnodeConfig/ValidatorConfig/g

* mv core/lib/fullnode.rs core/lib/validator.rs

* s/Fullnode/Validator/g

* Add replicator-x.sh

* Rename fullnode.md to validator.md

* cargo fmt

bench-exchange/src/bench.rs

@@ -892,9 +892,9 @@ pub fn airdrop_lamports(client: &Client, drone_addr: &SocketAddr, id: &Keypair,
 #[cfg(test)]
 mod tests {
     use super::*;
-    use solana::fullnode::FullnodeConfig;
     use solana::gossip_service::{discover_cluster, get_clients};
     use solana::local_cluster::{ClusterConfig, LocalCluster};
+    use solana::validator::ValidatorConfig;
     use solana_drone::drone::run_local_drone;
     use solana_exchange_api::exchange_processor::process_instruction;
     use solana_runtime::bank::Bank;
@@ -907,7 +907,7 @@ mod tests {
         solana_logger::setup();
 
         const NUM_NODES: usize = 1;
-        let fullnode_config = FullnodeConfig::default();
+        let validator_config = ValidatorConfig::default();
 
         let mut config = Config::default();
         config.identity = Keypair::new();
@@ -929,7 +929,7 @@ mod tests {
         let cluster = LocalCluster::new(&ClusterConfig {
             node_stakes: vec![100_000; NUM_NODES],
             cluster_lamports: 100_000_000_000_000,
-            fullnode_config,
+            validator_config,
             native_instruction_processors: [solana_exchange_program!()].to_vec(),
             ..ClusterConfig::default()
         });