wait daemon process until they stopped

- rake daemon:stop waits until three sub-processes (job_worker, analyzer_worker, service_worker) have stopped.
- The timeout is set to 30 sec. If these process do not stop after 30 secs, kill -9 are sent to these.
trivial refactoring
change the frequency of cache_updater

- change the frequency of cache_updater because the interval of cache_updating is longer than the timeout of 30 sec.
start and stop daemons in parallel
Merge pull request #204 from crest-cassia/wait_until_daemon_died

Wait until daemon dies