Merge pull request #8 from oliverzy/master

Meter: the start time is not initialized correctly
Meter: add ref/unref methods

Make it possible to ref and unref the timer that backs the meter.

Without an unref method, a running meter will keep the event loop alive
even when everything else has quit.  That of course is not always the
desired behavior.
test: remove meter.start monkey-patch

Meter#start() is an empty method as of commit 2dc9ce5, there is no
longer any need to monkey-patch it out.
Merge pull request #9 from bnoordhuis/ref-unref

Add ref/unref methods
Merge branch 'master' of https://github.com/felixge/node-measured into highres_timer

Conflicts:
	test/unit/metrics/test-Meter.js