Speed Up Simpletest.js

This patch makes simpletest.js perform its collapsing table rows trick faster. The current implementation causes slight delays on slower machines before it opens/closes, and uses unnecessarily intensive "fadeIn" and "fadeOut" jQuery methods when hiding/showing, even though table rows aren't capable of being faded in many browsers. I think the intention of using them might have been to simply intentionally slow down the effect. This patch takes a different approach and simply toggles visibility and uses a timer to control the expansion of rows, rather than intentionally grinding CPU cycles just to cause a delay.

Chx informs me this problem is especially noticeable in Opera. And in Konqueror the table expansion doesn't work at all. This patch works in Firefox, Opera, Konqueror, IE 6/7.