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/registry.c b/server/registry.c
index 2262f59..b766308 100644
--- a/server/registry.c
+++ b/server/registry.c
@@ -434,7 +434,7 @@
 static struct key *alloc_key( const WCHAR *name, time_t modif )
 {
     struct key *key;
-    if ((key = (struct key *)alloc_object( &key_ops, -1 )))
+    if ((key = alloc_object( &key_ops )))
     {
         key->class       = NULL;
         key->flags       = 0;