Extend mod_negotiation to evaluate the environment variables

no-gzip and gzip-only-text/html the same way as mod_deflate does.

(it drops all non-identity encodings, not only gzip)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@98871 13f79535-47bb-0310-9956-ffa450edef68