Support multiple Graphite inputs

[otoolep]

Fixes issue #3636

The fix for this issue is simple. Don't add any config objects for Graphite, let the toml package take care of it. Sensible Graphite defaults are still set when a Graphite service is itself initialized, though a small fix needed to be made to the Graphite config code.

Tested by enabling two Graphite TCP inputs via a config file, one on port 2003, a second on port 2004. Connectivity confirmed to each using telnet, and the logs showed both starting up.

[graphite] 2015/09/06 21:27:08 Starting graphite service, batch size 1000, batch timeout 1s
[graphite] 2015/09/06 21:27:08 Listening on TCP: [::]:2003
[graphite] 2015/09/06 21:27:08 Starting graphite service, batch size 1000, batch timeout 1s
[graphite] 2015/09/06 21:27:08 Listening on TCP: [::]:2004

[otoolep]

@jwilder @corylanou

[corylanou]

I think we should remove this code then if we aren't going to use it. It is confusing as most of the configs use a NewConfig and I can see a future change where we think we did something but we didn't because it is no longer called.

https://github.com/influxdb/influxdb/blob/multi_graphite/services/graphite/config.go#L51

Otherwise, +1

[otoolep]

Unused NewConfig removed, merging on green. Thanks @corylanou