Remove unused css and js compression

Since some time the minified css (tryton-sao.min.css) in the distributed package has the same size as the non-minified version. I checked this for some versions of 6.0 and for the latest version of 6.6.

The less project says:

Compress (Deprecated)

lessc --compress -x { compress: true }

Compress using less built-in compression. This does an okay job but does not utilise all the tricks of dedicated css compression. In general, we recommend looking at third-party tools that clean and compress CSS after your Less has been transformed to CSS.

Using cleancss from nodejs indeed worked for me to reduce the size for about 20%.