Added a subserver wrapper option to the http library. It should however only be used in experimental environments, because it is based on the undocumented CleanServer API, instead of stable pure Clean libraries.

Also moved the makeResponse function in the HttpServer, HttpCGI and HttpSubServer modules to a unified http_makeResponse function in HttpUtil


git-svn-id: https://svn.cs.ru.nl/repos/iTask-system/trunk@129 63da3aa8-80fd-4f01-9db8-e6ea747a3da2