Next submission link - fixes #19

Fix #19 
`afcHelper_submitTimestamp` is undefined...yeah, actually one of the goals of the rewrite is to avoid polluting the global scope.

I think you can probably access it as `afchSubmission.templates[0].timestamp` though... `afchSubmission.templates.length && afchSubmission.templates[0].timestamp` probably? (Haven't tested, I think this works though.)

Actually you can simplify this quite a bit:

```
cmstartsortkey: 'P' + ( ( afchSubmission.templates.length && afchSubmission.templates[0].timestamp ) / 100 ) + ( older ? 0 : 1 )
```