Ask the w3 WWW browser to load URL.
Default to the URL around or before point.
When called interactively, if variable `browse-url-new-window-flag' is
non-nil, load the document in a new window. A non-nil interactive
prefix argument reverses the effect of `browse-url-new-window-flag'.
When called non-interactively, optional second argument NEW-WINDOW is
used instead of `browse-url-new-window-flag'.
(fn URL &optional NEW-WINDOW)