This patch make several WSGI related alterations. First, it changes the server to be almost a generic WSGI server. Second, it changes request.py to have wsgiapplication and _wsgirequest. wsgiapplication is a class that creates _wsgirequests when called by a WSGI compliant server. It needs to know whether or not it should create hgwebdir or hgweb requests. Lastly, wsgicgi.py is added, and the CGI scripts are altered to use it to launch wsgiapplications in a WSGI compliant way. As a side effect, all the keepalive code has been removed from request.py. This code needs to be moved so that it is exclusively in server.py