[utils] run one_conn_awk_bench after bc-benchmark

It is too damn slow and not so informative as bc-benchmark.
Because it had only one connection to server.
[utils] move get_machine_info() into run_benchmarks.sh

Was in one_conn_awk_bench.sh
[utils] one_conn_awk_bench: add PING command
[utils] one_conn_awk_bench: testing not existed commands too.

For now for not-existed commands, commandserver print default error,
using boost::format() and now it is very slow.

Example (bc-benchmark) for boostcache with 1 worker:
PING:                  106382.98 requests per second
NOT_EXISTED_COMMAND:   61349.69 requests per second
[benchmark] benchmarking PING and non existed commands