feat(authentication): provide an authentication mechanism (#19)

* moves server into session

* renames jsonrpc server to jsonrpc proxy

* moves server into session

* renames jsonrpc server to jsonrpc proxy

* adds json rpc server

* removes obsolete proxy from protocol

* changes interface of jsonrpc_proxy_onresult to accept previously parsed messages

* adds infrastructure to process incoming requests; fixes invalid read of ill formatted responses

* adds description of authentication request

* adds authentication request

* adds userdb for authentication purposes

* removes debug code: console.log()

* fixes cmake build error (missing openssl symbols)

* fixes typo

* replaces ASCII art by UML diagram

* renames BAD_NOACCESS to BAD_ACCESS_DENIED

* fixes style

* adds docu of authentication

* ignored false positives of flawfinder

* fixes style issues

* fixes javascript style issues

example/daemon/www/js/webfuse/client.js

@@ -24,6 +24,16 @@ export class Client {
         };
     }
 
+    authenticate(type, credentials) {
+        const request = {
+            "method": "authenticate",
+            "params": [type, credentials],
+            "id": 42
+        };
+        
+        this._ws.send(JSON.stringify(request));
+    }
+
     disconnect() {
         if (this._ws) {
             this._ws.close();