* Change shortcode formatting to add a space before the self-closing trailing slash.
* Fix alignment of attachment previews with long filenames.
* Bug fix: Set an initial value on select fields (previously, no value would be set for a select field unless the user interacts with the field).
* Enhancement/fix: Reuse one copy of the media modal and reset its state upon closing, rather than creating duplicate markup each time the modal is accessed.
* Compatability: Uses "full" version of select2.js 4.0.3 to prevent plugin conflicts with other plugins which expect the full version to be enqueued.
* Compatability: Add `SELECT2_NOCONFLICT` flag to load Select2 in a unique namespace to prevent conflicts with other plugins which are loading select2.js version 3.
* Added Norwegian translation.
* Multiple coding style fixes.