unbinding the editor

```
I use the editor within a 'modal' dialog within the page (using colorbox). When
someone closes the dialog, I'd like to be able to cleanup after the editor has
been shown so that if they re-open the dialog, everything is fresh again.

This means unbinding any events and removing elements like the wmd-button-bar.
Would it be possible to add a editor.close() function?
```

Original issue reported on code.google.com by `latch...@gmail.com` on 20 Dec 2011 at 12:33

查看 pagedown 原始碼中的編輯器初始化程式碼，以了解事件和 wmd-button-bar 等 DOM 元素是如何繫結的。找出編輯器的主要類別或函式，然後設計一個清理方法，用來移除事件監聽器和 DOM 元素。建立一個開啟和關閉編輯器的模態對話框進行測試，以確保清理正常運作，且重新初始化時使用的是全新的狀態。

由索引模型根據 Issue 內容生成。