Implement registry key unloading.

diff --git a/server/request.h b/server/request.h
index a25dc50..8f9f9d6 100644
--- a/server/request.h
+++ b/server/request.h
@@ -206,6 +206,7 @@
 DECL_HANDLER(enum_key_value);
 DECL_HANDLER(delete_key_value);
 DECL_HANDLER(load_registry);
+DECL_HANDLER(unload_registry);
 DECL_HANDLER(save_registry);
 DECL_HANDLER(save_registry_atexit);
 DECL_HANDLER(set_registry_levels);
@@ -389,6 +390,7 @@
     (req_handler)req_enum_key_value,
     (req_handler)req_delete_key_value,
     (req_handler)req_load_registry,
+    (req_handler)req_unload_registry,
     (req_handler)req_save_registry,
     (req_handler)req_save_registry_atexit,
     (req_handler)req_set_registry_levels,