added comments to cache classes.

laravel/cache/drivers/driver.php

@@ -1,6 +1,4 @@
-<?php namespace Laravel\Cache\Drivers;
-
-use Closure;
+<?php namespace Laravel\Cache\Drivers; use Closure;
 
 abstract class Driver {
 

laravel/cache/drivers/file.php

@@ -1,6 +1,4 @@
-<?php namespace Laravel\Cache\Drivers;
-
-use Laravel\File as F;
+<?php namespace Laravel\Cache\Drivers; use Laravel\File as F;
 
 class File extends Driver {
 

laravel/cache/drivers/memcached.php

@@ -1,7 +1,4 @@
-<?php namespace Laravel\Cache\Drivers;
-
-use Memcache;
-use Laravel\Config;
+<?php namespace Laravel\Cache\Drivers; use Laravel\Config, Memcache;
 
 class Memcached extends Driver {