[+BUGFIX] Fixed column names bug Zend\Db\Sql\Select

Zend\Db\Sql\Select will prepare the column names incorrectly in the rare case when the table is specified with an alias (`array('alias' => 'table')`) but `columns()` is called with `$prefixColumnsWithTable = false`.

Example:

     $select = new Select();
     $select->from(array('x' => 'foo'))->columns(array('bar'), false);

I added a UnitTest case and fixed this bug.

I know this is a rare case but it might happen to someone some day.