Add `createAlert()` to application.js
Add `createAlert()` to application.js

`createAlert()` should be called whenever an error is caught, so the
user sees the whole error message in an alert instead of the app getting
into a broken state.

jeffkreeftmeijer/UitzendingGemist,jeffkreeftmeijer/UitzendingGemist,jeffkreeftmeijer/UitzendingGemist