Ring Availability

First pass at a more informative ring availability page.

![Overview][overview]
![Partition Information][partitions]

[overview]: http://cl.ly/image/0F1h3I1K3T42/Screen%20Shot%202013-06-06%20at%201.15.45%20PM.png
[partitions]: http://cl.ly/image/0u3n1g3W1D2O/Screen%20Shot%202013-06-06%20at%201.15.54%20PM.png

/cc @seancribbs @joedevivo @jgnewman