U++

Skylark user has currently no way to influence the headers sent in the response. This is IMHO wrong, especially for Cache-Control header which is currently hardcoded to "no-cache".

Attached patch adds two methods, ClearHeader() and SetHeader(), providing user full control. Intended usage would be for example tweaking the caching for static resources:

SKYLARK(Favicon, "/favicon.ico") {
    String icon = GetDataFile("favicon.png");
    String tag = IntStr64(GetFileTime(icon).ft);
    http.SetHeader("Cache-Control", "max-age=2592000");
    http.SetHeader("ETag", tag);
    if(http.GetHeader("if-none-match") != tag){
        http.ContentType("image/png") << LoadFile(icon);
    } else {
        http.Response(304, "Not Modified");
    }
}