rack/rack-contrib — pull request #84 by ericboehs (2014-01-16 10:54:27+00:00)
Title: Allow Etag/Last-Modified headers in Rack::StaticCache

Server side caching techniques shouldn't be disallowed.

See: https://github.com/rack/rack-contrib/commit/3f42d3afe7323d322567d77cd404fb5bd8d9f1eb#commitcomment-5084830