* change addedDate to join.
 * adjust db structure.
 * change addedDate to join.
 * change owners to moderators.
 * fix the error of menu highlight for board.
 * adjust the priviledge for front pages.
 * split reply from thread module.
 * adjust db structure.
 * use trigger instead.
 - delete it.
 * add the referer logic.
 * adjust code foramt.
 * change the pager lang items.
 + add method of canPost().
 * use canPost() instead.
 * change the owners field to moderators.
 * adjust the pager style.
 * adjust board page.
 - remove them, because they are from discuz.
 * adjust the forum-admin page.
 * adjust updateStats() method.
 * adjust code foramt.