BUGFIX: PrehLib::setMember() for useMemTypeTable

In addition to the camel-casing problem with useMemTypeTable
this was using the names of SQLManager methods that are used on Fannie
but not on the lane.
Might it be a good idea to make alias methods in lib/SQLManager.php
execute() as alias for exec_statement()
prepare() as alias for prepare_statement()
as is done, but in reverse, on the Fannie side?
```php
    public function execute($sql, $input_array=array(), $which_connection='')
    {
        return $this->exec_statement($sql, $input_array, $which_connection);
    }

    public function prepare($sql,$which_connection="")
    {
        return $this->prepare_statement($sql, $which_connection);
    }
```