Added my_global.h to compile after my_list.h is added to mysql.h
sql_prepare.cc:
  Handle close stmt from client
  Minor fixups to make SET variable=? to work
sql_parse.cc:
  Added missed COM_CLOSE_STMT
mysql_priv.h:
  Change mysql_stmt_close to mysql_stmt_free to not to conflict with client type
libmysql.c:
  Clean all open stmts during mysql_close() implicitly