dev #95747 add supports for memcached extension

VERSIONS_WIP/95747

+ - ticket #95747 : Bokeh supporte l'extension PHP memcached
\ No newline at end of file

library/startup.php

@@ -177,8 +177,15 @@ class Bokeh_Engine {
       : ['cache_dir' => PATH_TEMP ];
 
     // getting a Zend_Cache_Core object
+    $backend = 'File';
+
+    if ($use_memcached) {
+      $backend = extension_loaded('memcached')
+        ? 'Memcached'
+        : 'Memcache';
+    }
     $cache = Zend_Cache::factory('Core',
-                                 $use_memcached ? 'Memcached' : 'File',
+                                 $backend,
                                  $frontendOptions,
                                  $backendOptions);