support alternative non-JavaScript build

```
It would be nice if it was possible to build a version of an app that doesn't 
include any JS so that it can be instantly published in the iOS part of the 
pebble app store and that no changes need to be made to the app code and that 
the default config values are used.

Thanks!
```

Original issue reported on code.google.com by `fugouna...@gmail.com` on 7 Apr 2014 at 4:20
