Moved all references to file descriptors out of the generic object
structure.
Changed the poll()-related routines to deal with file descriptors
instead of objects and integrated poll support into fd.c.

diff --git a/server/timer.c b/server/timer.c
index 22e4e79..4ca7793 100644
--- a/server/timer.c
+++ b/server/timer.c
@@ -28,6 +28,8 @@
 #include <sys/types.h>
 
 #include "windef.h"
+
+#include "file.h"
 #include "handle.h"
 #include "request.h"