New plan. First, get proxy profiles working. Next, consider an API suitable for use by interactive
systems. The old define/remove system really doesn't work well with profile classes.

Barring any further comments or concerns, this will be the last revision before I start implementing.

{
    define_hook("proxy_switched_hook");

    function proxy_profile() {}
    proxy_profile.prototype = {};

    define_keywords("$http", "$ssl", "$ftp", "$gopher", "$socks", "$socks_ver",
                    "$socks_dns", "$excludes");
    function proxy_profile_manual(name) {}
    proxy_profile_manual.prototype = new proxy_profile();
    proxy_profile_manual.prototype.name = null;
    proxy_profile_manual.prototype.http = null;
    proxy_profile_manual.prototype.ssl = null;
    proxy_profile_manual.prototype.ftp = null;
    proxy_profile_manual.prototype.gopher = null;
    proxy_profile_manual.prototype.socks = null;
    proxy_profile_manual.prototype.socks_ver = null;
    proxy_profile_manual.prototype.socks_dns = null;

    function proxy_profile_auto_detect() {}
    proxy_profile_auto_detect.prototype = new proxy_profile();

    keywords("$retry_min", "$retry_max", "$timeout");
    function proxy_profile_auto_config(name, url) {}
    proxy_profile_auto_config.prototype = new proxy_profile();
    proxy_profile_auto_config.prototype.name = null;
    proxy_profile_auto_config.prototype.url = null;
    proxy_profile_auto_config.prototype.retry_min = null;
    proxy_profile_auto_config.prototype.retry_max = null;
    proxy_profile_auto_config.prototype.timeout = null;

    function proxy_profile_system() {}
    proxy_profile_system.prototype = new proxy_profile();

    function proxy_profile_null() {}
    proxy_profile_null.prototype = new proxy_profile();

    function proxy_profile_unmanaged() {}
    proxy_profile_unmanaged.prototype = new proxy_profile();

    let toggle_profile = null;

    function proxy_switch(profile) {}

    function proxy_toggle() {}
    interactive("proxy-toggle", "Toggle use of active profile.", function (I) {});

    function proxy_mode_line_formatter_default(profile) {}

    function proxy_mode_line_enable(formatter) {}
}