meters: copy dicts before getting an iterator
graphite: removed daemon=True from Thread() for python3.2 compatibylity
meters: process dump() exceptions
Changed respawn model, fixed "threads can only be started once"
Fixed #12: is_running_hook() for Python 3.4 + tests
meters.clean()
meters._get_placeholders_cache()
Fixed syntax error
Added start()/stop() tests
Construct handlers on a caller side
Removed busyloop from watcher