Issues57 - groundwork for monitoring 

This is just some of the groundwork for a new set of methods to manage and view monitoring information.  
Currently "sl monitor status" will just show you the SERVICE_PING results for each server, and the last date it was checked.

![screen shot 2014-10-29 at 2 59 35 pm](https://cloud.githubusercontent.com/assets/7408017/4833618/2e76f466-5fa6-11e4-8c82-9d2b98fd3394.png)


I wanted to get this pull request in early incase anyone has any architecture concerns.
This is a place where the current SL APIs are effecting the API of the manager too much. In the context of "monitoring", the fact that the target is hardware or virtual servers is a detail.