mysql_dt_base::std::string conversion operator is now const, to avoid warnings in certain circumstances with SSQLS.  See:
mysql_dt_base::std::string conversion operator is now const, to avoid
warnings in certain circumstances with SSQLS.  See:

	http://lists.mysql.com/plusplus/4385

Patch by Wolfram Arnold <wolfram@arnold.name>


git-svn-id: 1a57124bbb9aca193a920d0ffd753d488afb922b@616 5946f024-35f4-0310-b1b3-9a3be3380cfb

veprbl/mysqlpp,veprbl/mysqlpp,veprbl/mysqlpp