Doxygen-related changes and minor code modifications
diff --git a/model/sync-state.cc b/model/sync-state.cc
index 5e09655..4befe62 100644
--- a/model/sync-state.cc
+++ b/model/sync-state.cc
@@ -38,6 +38,8 @@
 
 typedef error_info<struct tag_errmsg, string> info_str; 
 
+using namespace Sync::Error;
+
 namespace Sync {
 
 #ifdef _DEBUG