Added processes to enable a user to login to a vending machine. Added a form that pops up over the game screen to allow login. Validated the user inputs for account number, serial number, username, and password. Look up the account and make sure it is valid. Look up the user and make sure they are valid. Look up the serial number within the account and make sure it exists. Later, need to check that the user has access to the machine (when additional users can be added to the account; not yet). Create a machine event to record the machine as accessed by that user, at that time. Modified user serialization to only return the username and their account number so we are not sending the encrypted passwords back to the browser. If all goes well, log the user into the machine and take the user to the root menu (which takes the machine out of game mode).