channelartlist标签新增limit属性支持，提升内容展示灵活性

$attlist &＃61;&＃39;typeid|0,row|20,cacheid|&＃39;;

$attlist &＃61;&＃39;typeid|0,row|20,cacheid|,limit|&＃39;;

$limit &＃61; trim(preg_replace(&＃39;#limit#is&＃39;,&＃39;&＃39;, $limit));
if($limit!&＃61;&＃39;&＃39;) $limitsql &＃61;" LIMIT $limit ";
else $limitsql &＃61;" LIMIT 0,$totalnum";

$dsql->SetQuery("SELECT id,typename,typedir,isdefault,ispart,defaultname,namerule2,moresite,siteurl,sitepath
FROM &＃96;#&＃64;__arctype&＃96; WHERE $tpsql ORDER BY sortrank ASC LIMIT $totalnum");

$dsql->SetQuery("SELECT id,typename,typedir,isdefault,ispart,defaultname,namerule2,moresite,siteurl,sitepath
FROM &＃96;#&＃64;__arctype&＃96; WHERE $tpsql ORDER BY sortrank ASC $limitsql");