AUI-1771 Display all events in scheduler's month view

This fixes scheduler's rendering to allow having month cells without fixed width. It also fixes some checks to make sure that setting the `displayRows` attribute to null or Infinity will work as expected. With these 2 together, scheduler now has the ability to display all events in the month view.

The rendering changes will also enable people who want features like https://issues.liferay.com/browse/AUI-1774 to do it by just extending the CSS, we won't have to do it on Alloy itself.