mq: fix qparents to return the correct parent when no patches are applied

mq: hg qnew -f should refresh the new patch qnew -f was originally meant to just skip the localchanges check. But, it currently discards the local changes, which is not at all what people expect. This patch changes qnew -f to create the new patch and then run hg qrefresh on it. The local changes will be in the new patch.

merge with crew.

merge with wsgi changes.

Put support for persistent connections back in.

Fix two small bugs that would've prevented the web interface and IPv6 from working.

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

Fix server to set up a more WSGI compliant environment.

import: parse email messages

Don't require opts['dry_run'] to be set to fix external tools like tailor.