Add test for #1178.

![screen shot 2014-11-05 at 13 13 53](https://cloud.githubusercontent.com/assets/724877/4921048/3d828874-6507-11e4-9ede-078e3858bb29.png)

@daffl stache imports the mustache helpers module where `getHelper` is defined, so this fixes the issue for both mustache and stache. https://github.com/bitovi/canjs/blob/master/view/stache/stache.js#L9