Closes#1990, Ref #3810
- Add `js-` prefix to jQuery calls throughout code and templates
- move MarkdownComponent classNames to template
- Fix back button on posts content preview
- Remove dead code for preview tabbing jQuery
Closes#2849
-wire up delete post action in ember admin
-refactor ember modal dialog
-override RESTAdapter.deleteRecord to workaround Ember expecting
an empty response body on DELETEs