was enabled a noCache param was always added to the URL. In some
cases it would add 2 noCache params.
To fix this, I added a skipPreventProxyCache param to the gateway method,
and page just passes $pairs and $skipPreventProxyCache to gateway.
Added tests to Url.t to test gateway, page, makeAbsolute and urlize
to bring its coverage up to 100%.
Added tests to Stow.t to bring it's coverage up to 100% as well.