added cadvisor meter for host and services

[finishes: #80456090]

![screen shot 2014-10-14 at 2 11 22 pm](https://cloud.githubusercontent.com/assets/923211/4635062/f8d74fda-53d5-11e4-9ab1-6dd3650c2373.png)

i did and had it that way at one point. it didnt simplify implementation i still needed the show method for the service name.. so i thought maybe it makes sense to have the host health and then pass the service name to get the service health metrics.. but splitting them if that makes more sense to have a separate endpoint for host and service is also fine with me.