uses a separate thread to continuously check for new jmx processes
lock on del jmx[version]
added shutdown for updater
update signal handler
fixed a typo
log every new version monitored

also change UPDATE_INTERVAL -> UPDATE_INTERVAL_SECONDS
add command information for logging
use with block for acquire/release semantics
Merge pull request #10 from optimizely/update-jmx-processes-continuously

Update jmx processes continuously