Fix default sort ref #110

this adds code to the model for list views and related list views so that if no sort order is manually specified (someone hasn't clicked a column header) then it checks to see if the performance preference for default sorting is turned on and uses the sort order specified for the module. ref issue #110 (closed)

modules/Vtiger/models/ListView.php

@@ -189,6 +189,10 @@ class Vtiger_ListView_Model extends Vtiger_Base_Model {
if(empty($orderBy) && empty($sortOrder) && $moduleName != "Users"){
$orderBy = 'modifiedtime';
$sortOrder = 'DESC';
+			if (PerformancePrefs::getBoolean('LISTVIEW_DEFAULT_SORTING', true)) {
+                                $orderBy = $moduleFocus->default_order_by;
+                                $sortOrder = $moduleFocus->default_sort_order;
+                        }
}
if(!empty($orderBy)){