- got rid of include/async.h
- fixed some overlapped issues in socket handling
- moved kernel32.CancelIo implementation to ntdll

diff --git a/server/signal.c b/server/signal.c
index 99d9b82..0fe7df3 100644
--- a/server/signal.c
+++ b/server/signal.c
@@ -71,7 +71,8 @@
     handler_poll_event,       /* poll_event */
     no_flush,                 /* flush */
     no_get_file_info,         /* get_file_info */
-    no_queue_async            /* queue_async */
+    no_queue_async,           /* queue_async */
+    no_cancel_async           /* cancel_async */
 };
 
 static struct handler *handler_sighup;