Keep it candy

Spurred by the latest addition to the Dolphin autocompleter done by Udo Schneider, I added some icons to the Seaside and Scriptaculous classes, this way will be easier to identify them (apart from its class prefix), and it will be nicer, as Dolphin itself is (well... Dolphin isn't nicer, it's definitely the nicest).

I'll publish this modification in the next release.