wycats/rake-pipeline-web-filters — pull request #43 by twinturbo (2012-09-02 14:56:50+00:00)
Title: HTML5 cache manifest filter

Title says it all. See the NOTE line. This is the only way this filter can be implemented until rake-pipeline has some sort of passthrough filter (https://github.com/livingsocial/rake-pipeline/issues/86).