Add parameter ignore(default:false) to playerLogin

So that client scripts can call all slots created by other client scripts (.connect) without touching anything.

This will be extremely useful for this: https://raw.github.com/TheUnknownOne/PO-Client-Tools/master/scriptLoader.js (emitSignals function)

```javascript
emitSignals: function () { // fixes scripts that use signals
            var net = client.network(); // there might be others that need to be emitted...
            
            //if (loggedIn) { // PO is broken :[
                //net.playerLogin(/*{}*/playerLoginArgs, client.getTierList()); // <-- this would have , true to completely fix this problem
            //}
            
            // instead using scriptLoader.loginHandlers.. Hoping people will use this
            scriptLoader.loginHandlers.forEach(function (value, index, array) {
                value(playerLoginArgs, sys.getTierList(), 1); // return 1 as 3rd argument to indicate that it was called by ScriptLoader
            });
            
            scriptLoader.loginHandlers = [];
            
            net.serverNameReceived(serverName);
            net.announcement(announcement);
            
        },
```