Fixed URL error with XenForo board not installed in root folder.

Fixed redirect URL error.

• Fix conflict with Hide BB Codes addon.
• Now support both regular URL & URL with preview.

• Add noindex tag for the redirect page.
• Fixed a conflict with a lot of add-ons related to BBCode (ex: D.C Style - Attachment View, HIDE BBCode, ...).
• Display the destination URL in the redirect page.