Cross-site scripting fixes by Robert Collins and Henrik Nordstrom

Cross-site scripting fixes by Robert Collins and Henrik Nordstrom

Everywhere where Squid inserts text received from the network into
a HTML page (error pages, FTP listings, Gopher listings, ...) care
must be taken to ensure that the text is properly encoded as HTML,
or a malicious user might be able to insert script code or other
HTML tags, and exploit the web browser of any user visiting their
page or clicking on that funny link received in a email..