cleanup api docs, add aggregates, health docs, fix a few errors

Full coverage of all api endpoints.  Moved away from monolithic page.

![screen shot 2013-06-08 at 9 51 13 pm](https://f.cloud.github.com/assets/242283/628420/908aaecc-d0af-11e2-94d0-f835fdcc1683.png)
![screen shot 2013-06-08 at 9 51 40 pm](https://f.cloud.github.com/assets/242283/628421/909de2f8-d0af-11e2-9590-006898b21ebe.png)