Logging and connection fixes.

* Add support for setting logging levels
* Re-use the same Etcd client instead of instantiaing a new one every reload
godep save -r rewrites all imports to something like

```
"github.com/mailgun/vulcand/Godeps/_workspace/src/github.com/mailgun/go-etcd/etcd"
```

In this case no additional changes are neccessary as long as it's a valid path that will work with the existing `GOPATH`.