Check return value of gmtime() and add error codes
where it fails in ASN1_TIME_set().

Edit asn1.h so the new error code is the same in 0.9.7
and 0.9.8, rebuild new error codes.

Clear error queue in req.c if *_min or *_max is absent.
diff --git a/CHANGES b/CHANGES
index 2fd057c..aa9a7ae 100644
--- a/CHANGES
+++ b/CHANGES
@@ -381,6 +381,10 @@
  
  Changes between 0.9.7 and 0.9.7a  [XX xxx 2003]
 
+  *) Under Win32 gmtime() can return NULL: check return value in
+     OPENSSL_gmtime(). Add error code for case where gmtime() fails.
+     [Steve Henson]
+
   *) DSA routines: under certain error conditions uninitialized BN objects
      could be freed. Solution: make sure initialization is performed early
      enough. (Reported and fix supplied by Ivan D Nestlerode <nestler@MIT.EDU>,