1. Use `this.` instead of `{{action}}` where applicable
2. Use `{{fn}}` instead of `@actionParam` where applicable
3. Use non-`@` versions of class/type/tabindex/aria-controls/aria-expanded
4. Remove `btn` class (it's added automatically to all DButtons)
5. Remove `type="button"` (it's the default)
6. Use `concat-class` helper
When editing the files for a theme in the admin dashboard, typing "cmd+s" (a common key-binding to save in most text editors) used to engage the browser's default "save page" dialogue.
This commit adds a key-binding to the ace editor that saves the file.
Now, the "cmd+s" (and "ctrl+s" for windows) key-binding does the same action as the save button.
