closes https://github.com/TryGhost/Ghost/issues/11707
- Firefox is different to every other browser and doesn't allow file input values to be reset by doing `input.value = null`
- outcome of reset not working is that Firefox won't trigger the change event when the same file is re-selected
- fixed by cloning the input element and replacing it
no issue
- ran [es5-getter-ember-codemod](https://github.com/rondale-sc/es5-getter-ember-codemod)
- [es5 getters RFC](https://github.com/emberjs/rfcs/blob/master/text/0281-es5-getters.md)
- updates the majority of `object.get('property')` with `object.property` with exceptions:
- `.get('nested.property')` - it's not possible to determine if this is relying on "safe" path chaining for when `nested` doesn't exist
- `.get('config.x')` and `.get('settings.x')` - both our `config` and `settings` services are proxy objects which do not support es5 getters
- this PR is not exhaustive, there are still a number of places where `.get('service.foo')` and similar could be replaced but it gets us a long way there in a quick and automated fashion
closes https://github.com/TryGhost/Ghost/issues/9321
- don't use `dataTransfer.effectAllowed` in IE11
- only fire the action in `{{gh-file-input}}` if there are files selected to prevent a double call to the action due to resetting the input
closes https://github.com/TryGhost/Ghost/issues/9266
- `emberx-file-input` passes a `resetInput` function through to it's action handler but we weren't doing that in our override component. Added the missing functionality and updated all of our handlers to use that instead of doing manual resets
- added a `setFiles` action to `{{gh-uploader}}` and yield it for use in block invocations
no issue
- override `x-file-input` in `gh-file-input` to look for a custom property on the change event if we are in testing mode (this is necessary because Ember 2.5+ use native rather than jQuery events so `target.files` is readonly, see https://github.com/emberjs/ember.js/issues/13540)
- migrate unit tests for the uploader components to the integration tests
- add skipped acceptance tests for the subscribers CSV import now that it's possible to simulate file uploads
