GenerateMigrationsDiff task does not use new order of changeColumn()

The GenerateMigrationsDiff task generates migrations which still use the old ordering of parameters of changeColumn().

This is how it gets generated:

$this->changeColumn('my_table', 'my_column', '25', 'timestamp', array(
'notnull' => '1',
));

Why it should be like this

$this->changeColumn('my_table', 'my_column', 'timestamp', '25', array(
'notnull' => '1',
));

I also added a patch to fix this.