fixed bug #76168, attribute redeclared in the internal subset should not

* valid.c SAX.c: fixed bug #76168, attribute redeclared in
  the internal subset should not raise duplicate ID errors,
  also there was a small bug in conjunction to namespace
  declarations defaulted and xml:xxx attributes DTD definitions.
Daniel
diff --git a/nanohttp.c b/nanohttp.c
index b843370..f0d3062 100644
--- a/nanohttp.c
+++ b/nanohttp.c
@@ -39,6 +39,9 @@
 #ifdef HAVE_NETDB_H
 #include <netdb.h>
 #endif
+#ifdef HAVE_RESOLV_H
+#include <resolv.h>
+#endif
 #ifdef HAVE_FCNTL_H
 #include <fcntl.h> 
 #endif