Fixed a very nasty bug in FIB iterators.

TODO

@@ -4,8 +4,6 @@ Core
 - client: paging?
 - client: data losses on large dumps?
 
-- table: ocassional core dumps in rt_prune()
-
 Documentation
 ~~~~~~~~~~~~~
 - write doctool

nest/route.h

@@ -42,9 +42,9 @@ struct fib_node {
 
 struct fib_iterator {			/* See lib/slists.h for an explanation */
   struct fib_iterator *prev, *next;	/* Must be synced with struct fib_node! */
-  struct fib_node *node;		/* Or NULL if freshly merged */
   byte efef;				/* 0xff to distinguish between iterator and node */
   byte pad[3];
+  struct fib_node *node;		/* Or NULL if freshly merged */
   unsigned int hash;
 };