Handle Ctrl+D aka EOF

[jotuel]

In netcat nc localhost 6667 if you type NI'CTRL+D'CK something the parser should be able to take both messages and parse them together. Currently only later part is used leading to unknown commands and such. Solution is simply to make a RecvParser class for each Client class, including the msg_queue. However this leads to Message in QuitCommand being destroyed before its finished as the Client gets erased.

Need to mark Client for destruction and destroy only after QuitCommand is out of scope. As a Message reference is still there. Switching to shared_ptr kept the program alive, as it should keep it alive longer, but Valgrind still complains.

[jotuel]

Found a neater way to do this which is to check if command is QUIT and execute returning false from CommandDispatcher. That way no quit deleted objects are touched again and Valgrind is happy.