Improve integration between <gxml> / <gtext> / <gbutton> and SiteBuilder by ensuring that 401 responses are propagated back to the browser which then can resend proper auth headers to access edit area versions of various subresources (textures, backgrounds etc). Fixes [bug 4486 (#4486)] and potentially [RT#13455] as well. Rev: server/base_server/roxen.pike:1.1030 Rev: server/etc/modules/GText.pmod:1.21 Rev: server/etc/modules/LazyImage.pmod/module.pmod:1.21 Rev: server/modules/graphics/gbutton.pike:1.118 Rev: server/modules/graphics/graphic_text.pike:1.306 Rev: server/modules/graphics/gxml.pike:1.40