sanon: Fix flags and ctx export/import confusion

We were passing SANON flags to _gss_mg_import_rfc4121_context(), which
wants GSS flags.  Meanwhile, I broke gss_inquire_context() on imported
SAnon contexts when I did my review of SAnon.

This commit fixes both issues and removes SANON_FLAG_*, which were only
ever needed because of a flag to track whether a context was locally
initiated or accepted.  Now we use a separate int field of the sanon_ctx
to track whether a context was locally initiated.  Once an SAnon context
is fully established, we rely on gss_inquire_context() on the rfc4121
sub-context for all metadata that isn't the initiator and acceptor names
nor the mechanism OID.

lib/gssapi/sanon/export_sec_context.c

@@ -46,9 +46,7 @@ _gss_sanon_export_sec_context(OM_uint32 *minor,
     }
 
     major = gss_export_sec_context(minor, &sc->rfc4121, interprocess_token);
-    if (major == GSS_S_COMPLETE) {
-	_gss_sanon_delete_sec_context(minor, context_handle,
-				      GSS_C_NO_BUFFER);
-    }
+    if (major == GSS_S_COMPLETE)
+        _gss_sanon_delete_sec_context(minor, context_handle, GSS_C_NO_BUFFER);
     return major;
 }