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/atom.c b/server/atom.c
index 78378cf..e14c05e 100644
--- a/server/atom.c
+++ b/server/atom.c
@@ -101,7 +101,7 @@
 {
     struct atom_table *table;
 
-    if ((table = alloc_object( &atom_table_ops, -1 )))
+    if ((table = alloc_object( &atom_table_ops )))
     {
         if ((entries_count < MIN_HASH_SIZE) ||
             (entries_count > MAX_HASH_SIZE)) entries_count = HASH_SIZE;