vpulim/node-soap — pull request #425 by aduyng (2014-07-30 15:16:05+00:00)
Title: Support authenticate async callback 

Change method authenticate(security) to authenticate(security, callback) to support async logic (e.x. checking username/password stored in database).
```javascript
soap = server.listen(....);
soap.authenticate = function(security, callback) {
'use strict';

var password, username, token;
token = security.UsernameToken;
username = token.Username;
password = token.Password;
//perform database lookup
databaseLookup(username, function(err, doc){
if( err ){
callback(false);
return;
}
callback(doc);
});
}

```