public static function unstaged()
	{
		$available = static::available();
		
		foreach( $available as $key => $migrations )
		{
			foreach( $migrations as $time => $migration )
			{
				if ( $time <= static::$config->get( $key.'.revision', 0 ) )
				{
					unset( $available[$key][$time] );
				}
			}
		}
		
		return $available;
	}