prompt user for http authentication info
in interactive mode, mercurial now asks the user for the username and
password when the server requires it. the previous behavior was to fail
with an http 401.
based on patch from eric jaffe <jaffe.eric@gmail.com>.
Thomas Arendsen Hein <thomas@intevation.de> [Sun, 14 May 2006 18:24:32 +0200] rev 2280
On Windows look for mercurial.ini in $USERPROFILE, too, if available
as os.path.expanduser('~') does not always yield a useful directory.
Based on a patch from Edouard Gomez <ed.gomez@free.fr>