update demo scripts

* add setup to combine init steps, configurable initial mint
  * bash -e -> bash and be explicit about errors with || exit $?
  * feed transaction logs to validator, too

multinode-demo/leader.sh

@@ -5,4 +5,6 @@ export RUST_LOG=${RUST_LOG:-solana=info}
 
 set -x
 [[ $(uname) = Linux ]] && sudo sysctl -w net.core.rmem_max=26214400
-cargo run --release --bin solana-fullnode -- -l leader.json < genesis.log
+
+cargo run --release --bin solana-fullnode -- \
+      -l leader.json < genesis.log tx-*.log > tx-"$(date -u +%Y%m%d%k%M%S%N)"