Add Cookie::forever constant, fixes #660

Signed-off-by: Colin Viebrock <colin@viebrock.ca>

laravel/cookie.php

@@ -2,6 +2,13 @@
 
 class Cookie {
 
+	/**
+	 * How long is forever (in minutes).
+	 *
+	 * @var int
+	 */
+	const forever = 525600;
+
 	/**
 	 * The cookies that have been set.
 	 *
@@ -96,7 +103,7 @@ class Cookie {
 	 */
 	public static function forever($name, $value, $path = '/', $domain = null, $secure = false)
 	{
-		return static::put($name, $value, 525600, $path, $domain, $secure);
+		return static::put($name, $value, static::forever, $path, $domain, $secure);
 	}
 
 	/**