SyntaxError: unreachable code after return statement

There are multiple instances of early returns. They show as warnings in FireFox. Perhaps I am missing something, but AFAIK they should all be removed or at least documented.

Example:

``` javascript
function prefetchCollections() {
return;

$.ajax({
type:'get',
url: '/ep/invite/recent-groups',
data: {
excludeIds: _getPadCollectionsIds()
},
```

src: https://github.com/dropbox/hackpad/blob/8235d75a2f242490b676e7b628170653051f46ab/etherpad/src/static/js/pad_collections.js#L198

Other examples:
- https://github.com/dropbox/hackpad/blob/8235d75a2f242490b676e7b628170653051f46ab/etherpad/src/static/js/pad_collections.js#L127
- https://github.com/dropbox/hackpad/blob/8235d75a2f242490b676e7b628170653051f46ab/etherpad/src/static/js/ace2/ace_media.js#L285
- https://github.com/dropbox/hackpad/blob/8235d75a2f242490b676e7b628170653051f46ab/etherpad/src/static/js/ace2/ace_media.js#L303