We stopped providing a way to set them, so don't render them either.

Also cleanup some leftover config options.

* Improve compressions + add expire headers
* Remove MSIE check, caching only for versioned files, do not gzip MP3/JPG/PNG
* Lower GZIP min length, enable compressions on WASM

* first pass at mod_muc_domain open source plus example

* doc - prosody config and config.js examples for mapper