Issue when creating guest (possibly due to the number of characters in the temporary username which is too large)

Hi,

I am currently attempting to create a guest with Combu, but I systematically fail to do so. After a bit of debugging, it seems the issue comes from the fact that the temporary username set in the function CreateRandom in Account.php has more characters that the table `Account` in the database is authorising. More precisely, here is the line of code for the temporary username in Account.php:

$new->Username = "__TEMP__".session_id() ."_".time();

When I created the database, I used the following code generated by COMBU: 

CREATE TABLE IF NOT EXISTS `Account` ( `Id` bigint NOT NULL AUTO_INCREMENT, `Username` varchar(45) NOT NULL, `Password` varchar(45) NOT NULL, `LastLoginIp` varchar(255) DEFAULT NULL, `LastLoginDate` datetime DEFAULT NULL, `Email` varchar(255) DEFAULT NULL, `ActivationCode` varchar(10) DEFAULT NULL, `ChangePwdCode` varchar(10) DEFAULT NULL, `Enabled` tinyint(1) NOT NULL DEFAULT '1', PRIMARY KEY (`Id`), UNIQUE KEY `AccountUsername` (`Username`), KEY `AccountPassword` (`Password`) ) ENGINE=InnoDB DEFAULT CHARACTER SET=utf8;

which allows only 45 characters for the username. 

First of all, I would appreciate if you could confirm me that this is indeed the issue.

Second, to fix it, I suppose I could either change the code for the temporary username to make it smaller (for example, by removing '__TEMP__' in the string) or increase the number of characters of `Username` in the table. Nevertheless, I am not sure which would be better. Do you have any advice?

Any help/suggestions would be appreciated.