Websocket initial implementation (#9)

* Added listener and session classes.

* Added client session class.

* Fixed minor code issues.

* Initial server implementation p2p connection

* Added a seperate thread to run the two servers

* Implemented basic web socket architecture

* Implemented basic peer to peer socket network

* Added a sample message

* Initial socket architecture completed

* Improved code readability

* Improved comments

src/main.cpp

@@ -82,5 +82,5 @@ int parse_cmd(int argc, char **argv)
     cout << "hpcore <command> <contract dir> (command = run | new | rekey)\n";
     cout << "Example: hpcore run ~/mycontract\n";
 
-    return -1;
-}
+    return 0;
+}