implement CLI command mesos-status

This commit implements the CLI command mesos-status, which reports three categories of hosts:

(1) The hosts that are reported by the master/state.json and responded correctly to monitor/statistics.json query;
(2) Those that are reported by master but responded incorrectly to query;
(3) Those that are included in the var/mesos/deploy/slaves files but not reported by the master.

In addition, the two functions ulimit and resolve are extracted from the original mesos-ps file as cli_utils because they will be likely reused in other CLI commands.