Allow an option for variable row heights

[dotdreaming]

Could there be an option to have row heights a fixed or variable height. If Fixed then the height of the scroller container will be determined by the number of items set in "max_items" option. But if row height is set to Variable then the height of the Container could be set with a new Height option.
Obviously if the variable row height is set then you cannot determine how many items will be displayed in the height of the scroller container, it could show three, two if one of the rows contains a lot of text or three and a half of the fourth.