Merge isisd into the Quagga's framework:
  - add privs support
  - use misc quagga's definitions
  - make it compile"able"
  - fix segfault cases related to hostname()
  - add debug isis xxx command

This patch has been approved by Paul Jakma.
diff --git a/lib/log.h b/lib/log.h
index 69919b4..8948ea0 100644
--- a/lib/log.h
+++ b/lib/log.h
@@ -47,6 +47,7 @@
   ZLOG_OSPF,
   ZLOG_RIPNG,  
   ZLOG_OSPF6,
+  ZLOG_ISIS,
   ZLOG_MASC
 } zlog_proto_t;