This chapter should describe what is installed by default, and how users can use an authorization-enabled server, doing this at a high level before descending into details. 

I think the intro should say:

- Both the server and the clients are integrated with SASL
- SASL uses the account a program is running in to identify the user and supply authentication
- As we install it, you have to run the server either as root or as the qpidd user - if you run as a daemon, this happens automatically, but if you run from the command line authentication can be trickier
- A 'guest' account is created by the installation program
- You can set up other accounts or see what accounts exist (see later discussion of saslpasswd2 and sasldblistusers2)


Some details for the further discussion:

- default authentication depends on the cyrus configuration on the box, it is not usually PLAIN
- need to discuss using the guest account in clients vs. connecting using the user account
- need to discuss ANONYMOUS authentication