Upgraded to CKEditor 4.0.0

This brings with it some removal of configuration overrides (in
config.js) due to our previous settings now being default with CKEditor.

A new plugin has also been added, MediaEmbed, which lets you easily add
YouTube videos. "Paste From Word" has also been removed, instead just
use "Paste as Plaintext".

Conflicts:
	public/assets/js/ckeditor/ckeditor.js
	public/assets/js/ckeditor/lang/_languages.js
	public/assets/js/ckeditor/lang/en.js
	public/assets/js/ckeditor/plugins/flash/dialogs/flash.js
	public/assets/js/ckeditor/plugins/image/dialogs/image.js
	public/assets/js/ckeditor/plugins/link/dialogs/anchor.js
	public/assets/js/ckeditor/plugins/link/dialogs/link.js
	public/assets/js/ckeditor/plugins/specialchar/dialogs/specialchar.js
	public/assets/js/ckeditor/plugins/tableresize/plugin.js
	public/assets/js/ckeditor/plugins/tabletools/dialogs/tableCell.js
	public/assets/js/ckeditor/skins/kama/dialog.css
Enable CKEditor forcePasteAsPlainText by default