Improve events

Add known clients (cache) for leaving clients
Add message to returned json object

src/parameter.rs

@@ -44,7 +44,7 @@ pub fn parameter_parse(params_str: &str) -> ParameterList {
 
     let mut response_params = ParameterList::new();
     parts.iter().for_each(|part| {
-        let (key, value) = part.split_once('=').unwrap_or((part, "1"));
+        let (key, value) = part.split_once('=').unwrap_or((part, ""));
         response_params.insert(key.to_string(), decode_value(value));
     });