+=item CustomerInfo
+
+Return a hashref of customer information, including all fields from
+C<cust_main> as well as:
+
+- AgentName: the name of the customer's agent
+- CustomerClass: the name of the customer's class
+- CustomerTags: an arrayref of tags attached to the customer, each
+ as a hashref with keys "name", "desc", and "color".
+- Referral: the name of the customer's advertising source.