Switch to file as default session driver.

app/config/session.php

@@ -11,12 +11,12 @@ return array(
 	| requests. By default, we will use the lightweight native driver but
 	| you may specify any of the other wonderful drivers provided here.
 	|
-	| Supported: "native", "cookie", "database", "apc",
+	| Supported: "file", "cookie", "database", "apc",
 	|            "memcached", "redis", "array"
 	|
 	*/
 
-	'driver' => 'native',
+	'driver' => 'file',
 
 	/*
 	|--------------------------------------------------------------------------