Merge pull request #9 from abh/master

Minor clarification to the README
Added MarshalJSON method to registry
Merge branch 'arikfb-master'
go fmt
Add debug.GCStats option.
Better controlled update of debug.GCStats.Pause.
Fix #12: switch to Go 1 standard time.Duration.

It's about time.
Update docs.
Close Graphite connections.
never-read debugging tool.
Style upgrade.
Add output to io.Writer, including ioutil.Discard.
Don't acquire registry lock for runtime metrics.
Don't hold the lock during Each callbacks.
go fmt
Benchmark for testing new EWMA.
Use a lock instead of a goroutine for EWMA.

In this instance, it's way faster.
Style upgrade.
Use a lock instead of a goroutine for Samples.
Style upgrade.