Adding cache lifetime option to smarty config

* 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

.gitignore

@@ -1,3 +1,4 @@
 /public/include/config/global.inc.php
 /public/templates/compile/*.php
 /cronjobs/logs/*.txt
+/public/templates/cache/*.php

public/include/config/global.inc.dist.php

@@ -358,13 +358,20 @@ $config['cookie']['domain'] = '';
  *
  *   Ensure that the folder `templates/cache` is writable by the webserver!
  *
- *  Options:
- *    0  =  disabled
- *    1  =  enabled
+ *   cache           =  Enable/Disable the cache
+ *   cache_lifetime  =  Time to keep files in seconds before updating them
  *
- *  Default:
- *    0  =  disabled
+ *  Options:
+ *    cache:
+ *      0  =  disabled
+ *      1  =  enabled
+ *    cache_lifetime:
+ *      time in seconds
+ *
+ *  Defaults:
+ *    cache           =  0, disabled
+ *    cache_lifetime  =  30 seconds
  **/
-$config['cache'] = 0;
-
+$config['smarty']['cache'] = 1;
+$config['smarty']['cache_lifetime'] = 30;
 ?>

public/include/smarty.inc.php

@@ -20,6 +20,7 @@ $smarty->template_dir = BASEPATH . 'templates/' . THEME . '/';
 $smarty->compile_dir = BASEPATH . 'templates/compile/';
 
 // Optional smarty caching, check Smarty documentation for details
-$smarty->caching = $config['cache'];
+$smarty->caching = $config['smarty']['cache'];
+$smarty->cache_lifetime = $config['smarty']['cache_lifetime'];
 $smarty->cache_dir = BASEPATH . "templates/cache";
 ?>