General question: What do you think about having `isPullRequest` take the issue as an argument?

My reasons;
 * The template is defining the name of `issue` so if the name is changed it is easy to remember to change it here
 * The function can be moved around in the backend (up the scope tree) with no ill effect since it no longer depends on a value defined by someone else existing.

Essentially, this stems from our previous conversations and the concern about keeping track of where values come from.  Here I think passing the value to the method makes the template more explicit.

```html
<li ng-if="isPullRequest(issue)" class="pull">pull</li>
```

I am not sure if this should be a general rule or not but it seems valid to pass these functions the data they need instead of using "magic", my head hurts now.