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.
useful when creating the Stow'ed variable.
When you ->get a Stow variable, you get a reference if you've
stowed an array or hash. So when you modify what you got, it
changes the original inside Stow and you don't need to do a ->set.
This wouldn't work for scalars, unless it was a scalar reference.
This also means that if you modify the variable you stowed (and you
stowed a reference) after you stowed it then the stow will change
as well.
