#298 dbtables() fails for MariaDB ODBC

[Richard H. McCullough]

dbtables() produces no output, even though dbcolumns() does if you know table name.
sql(d,"show tables") does produce output, which can be displayed using while row := fetch(d).
sql(d,"show databases") also produces output, which can be displayed using while row := fetch(d)
MariaDB is supposed to be compatible with MySQL.
I did my initial work using HeidiSQL before I installed ODBC Connector and used Microsoft ODBC menu.