Summarize operations in the top level hash keys

This pull request aims to make it easier to see what is going on inside a Moped instrumentation event.

### Before
![Schermafbeelding 2013-04-11 om 17 22 04](https://f.cloud.github.com/assets/1336311/368256/a214b43e-a2bb-11e2-9d55-f68df89d5a56.png)

### After
![Schermafbeelding 2013-04-11 om 14 45 07](https://f.cloud.github.com/assets/1336311/368261/af2c2792-a2bb-11e2-8d24-050da08c5a3f.png)