The URL in <meta http-equiv="Refresh" content="42; URL=target.html">
can now freely contain spaces and semicolons. There cannot be other
parameters between the delay and the URL. If the URL is not quoted,
then it spans to the end of the attribute, except not to trailing
spaces. If the URL is quoted, then it ends at the first closing
quotation mark. All this is consistent with Debian Iceweasel 3.5.16.
