new debug feature for DBAgent (output SQL statements when error)

git-svn-id: svn://zjseek-svn/common_libs/HexagonFramework/trunk@29 cda8b1a2-6144-11e3-ae32-65f4be330e90
Merge commit '888beae319441f1f6ae901cc0a4049a9d0cb58ad'