Adding routine which auto-refreshes `/wp-content/advanced-cache.php` when/if the entire `/wp-content/cache` directory is wiped out. Quick Cache now creates a special file `/wp-content/cache/qc-advanced-cache.time`. If this file is wiped out (e.g. the entire `/wp-content/cache` directory is wiped out);, and Quick Cache is enabled; the `/wp-content/advanced-cache.php` file is regenerated automatically with the current Quick Cache configuration. This makes Quick Cache a little friendlier to site owners running on the ElasticBeanstalk and other hosting platforms like it.