Facia defaults 2

This brings (back) facia defaults. We had taken it out because we changed completely how the JSON is structured AND subsequently changed how the agents worked.

I did it in a nice functional way, but decided to make it a really simple JSON string as then it's easier to change.
(If you are interested, before this I *did* have it inside `Lists` and `Maps`, but I could see no reason to keep it. Check the commits!)

I was thinking about putting this into a separate JSON file, but I am not sure what the best location of it would be inside the project.

This basically just starts the agents with a default value, and hits refresh `onStartUp` with `isWarmedUp=false` in order it to ignore what happens to the request for our `collection.json` in `S3`. This means that if it doesn't exists (Because the config is wrong, for example), or any other failure, then it just returns a `Nil`.

This PR has a similar effect as #2070 from the past.

Note that there is nothing stopping us from perhaps putting in what exists in `skeleton` as the `FaciaDefaults` in `Facia`. Maybe sometime in the future when it settles.

The default for `/uk`:
![defaultuk](https://f.cloud.github.com/assets/445472/1822540/75283cae-7162-11e3-8fee-79bcf170d820.png)