* Renamed configuration array to `smarty` => `cache`
* Added `smarty` => `cache_lifetime` to expire cache files properly
This should be safe to use, be aware that each page request is cached!
That includes any POST/GET calls to the site.
It does help in speeding up the site, up to 100% on some requests. For a
high traffic site it probably makes sense to enable this option with a
low cache lifetime to ensure most recent data.
Addresses #309
3449d5c29c