You can find the full source code for this website in the Seam package in the directory /examples/wiki. It is licensed under the LGPL.
wait state is a continuation. Each <page> node in a pageflow definition or <task> node in a business process definition is a jBPM wait state. Speaking more approximately, you might like to think of the conversation state as a continuation. (We do not usually talk in this kind of language because it is too mysterious-sounding and obfuscates simple concepts to make them seem more impressive.)