Fix CKEditor Korean line break issue in iOS #932

- iOS에서는 divarea 플러그인과 @largeden 님의 ios_enterkey 플러그인을 사용
- iOS에서는 divarea 플러그인과 호환되지 않는 에디터 컴포넌트를 로딩하지 않음
  - 추후 호환성 문제가 해결되면 다시 사용하도록 변경할 수 있음
- 기본 폰트 등의 스타일이 cke_wysiwyg_div 클래스에도 적용되도록 조치함

common/js/plugins/ckeditor/ckeditor/plugins/divarea/plugin.js

@@ -0,0 +1,38 @@
+/**
+ * @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @fileOverview The "divarea" plugin. It registers the "wysiwyg" editing
+ *		mode using a DIV element.
+ */
+
+CKEDITOR.plugins.add( 'divarea', {
+	afterInit: function( editor ) {
+		// Add the "wysiwyg" mode.
+		// Do that in the afterInit function, so it'll eventually overwrite
+		// the mode defined by the wysiwygarea plugin.
+		editor.addMode( 'wysiwyg', function( callback ) {
+			var editingBlock = CKEDITOR.dom.element.createFromHtml(
+					'<div class="cke_wysiwyg_div cke_reset cke_enable_context_menu" hidefocus="true"></div>'
+				);
+
+			var contentSpace = editor.ui.space( 'contents' );
+			contentSpace.append( editingBlock );
+
+			editingBlock = editor.editable( editingBlock );
+
+			editingBlock.detach = CKEDITOR.tools.override( editingBlock.detach,
+				function( org ) {
+					return function() {
+						org.apply( this, arguments );
+						this.remove();
+					};
+				} );
+
+			editor.setData( editor.getData( 1 ), callback );
+			editor.fire( 'contentDom' );
+		} );
+	}
+} );

common/js/plugins/ckeditor/ckeditor/plugins/ios_enterkey/plugin.js

@@ -0,0 +1,24 @@
+/**
+ * iOS enter key fix for IME
+ *
+ * https://github.com/rhymix/rhymix/issues/932
+ */
+CKEDITOR.plugins.add( 'ios_enterkey',
+{
+	icons: 'ios_enterkey',
+	init: function(editor)
+	{
+		editor.on('contentDom', function()
+		{
+			var editable = editor.editable();
+			editable.attachListener(editable, 'keyup', function(e)
+			{
+				if(e.data.getKey() === 13)
+				{
+					$(editor.document.$).find('.cke_wysiwyg_div').blur();
+					$(editor.document.$).find('.cke_wysiwyg_div').focus();
+				}
+			});
+		});
+	}
+});