master: networking: Now we can handle interrupted server connection gracefully
    -- fixed bug in allocating client id by using an extra heap for storing free id
    -- improved startup logic robustness; only start timer when all clients arrive
    -- fixed bug in id generating; reset all id counter to 0 after parsing a map
    -- added error prompt screen in client side; now when server is down, client can
       restart connection gracefully; added TO_MENU_AFTER_ERROR in application callback info