disable output-cache and force the browser to not cache the response when in debug mode

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@4163 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
mod_pagespeed optimizations & support

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@4164 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
build auto version (3046) ...

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@4165 1f8fe7d8-47f0-464c-8d0a-336f4953ab05