Revert "後台寫入ebc_issue_embed"

This reverts commit 56363d6b0ba586e9bdba021d809254ef4ba33211.
Revert "ebook前台顯示ebc_issue_embed"

This reverts commit e9f971f82a3c036134a5361c33e552eaee5e7fc6.
外部連結改為issue嵌入碼
刪除後台ebook的小圖及大圖區
using ['base_all_tpl'] in ebook.php
設定ebook的左選單
以外部連結(issue嵌入碼)直接顯示
引入issuu的js lib
download改ebook