Img substitution generates correct URLs but the substitution load seems to fail?

Still won't parse  some bits

This version of the code works *IF* all CSS URLs are relocated to trusted locations - IE, the local server.

After this I will be continuing my work attempting to do URL rewrites for arbitrary purposes in support of this PR and direct PDF creation.

This feature works in two parts.

This first part is by adding a prioxy-passthrough for resources. This enables the code to get around XSS issues we were previously having,.

The second part clones the first page, massages URLs in it's <Links>, <style>, and <img> tags to use the
L to load the resources then generate two thumbnails. One is 115px tall and the other is set at 50% the page height. Currently, only the smaller of the two is stored as a new BrewStub field.