Unify modified/created times

The former implementation meant that it was not guarantee that
the times automatically generated for the modified/created fields
would be exactly the same for a given operation.

lib/Cake/Model/Model.php

@@ -1662,13 +1662,14 @@ public function save($data = null, $validate = true, $fieldList = array()) {
 		}
 
 		$db = $this->getDataSource();
+		$now = time();
 
 		foreach ($dateFields as $updateCol) {
 			if ($this->hasField($updateCol) && !in_array($updateCol, $fields)) {
 				$default = array('formatter' => 'date');
 				$colType = array_merge($default, $db->columns[$this->getColumnType($updateCol)]);
 				if (!array_key_exists('format', $colType)) {
-					$time = strtotime('now');
+					$time = $now;
 				} else {
 					$time = call_user_func($colType['formatter'], $colType['format']);
 				}