Added markdown to running notes generated after 2014-12-18

Will update date to 2015-01-01 when we go live on production.
OK, couldn't find anything like it in Tornado either...

Top level: Define it as a global variable in utils.py, with indent 0 (zero), same as for a ```class``` or top-level function ```def```. That is, outside of any class or function.

Also, I would uppercase the name to signify that it is really a constants, although in principle one could mess around with it:

```python
ERROR_CODES = {
    400: 'Bad Request',
...
}
```