/// <summary>
/// Renames a tag in the system, and updates all pages that use it.
/// </summary>
/// <returns>Redirects to the Tools action.</returns>
public ActionResult RenameTag(string oldTagName, string newTagName)
{
TempData["Message"] = SiteStrings.SiteSettings_Tools_RenameTag_Message;
PageManager manager = new PageManager();
manager.RenameTag(oldTagName, newTagName);
return RedirectToAction("Tools");
}