height option for dialog

In general, the dialog seems to open to a set height of ~250px by default which is somewhat unexpected and is too tall for an average confirmation/message but too small for a form. It would be more useful if it auto fit the content length and had a maxHeight default set to something reasonable like 400px so it would fit on an average 1024x768 screen without scrolling. It's a pain/dangerous to have to set an explicit height every time.

This should behave like a normal block element that expands to the content as much as possible. I get worried about setting a fixed pixel height because font sizes and content lengths could very and you really want to avoid scrollbars on dialogs as much as possible.