web interface: customer session - this persists beyond carts, so the customer can retrieve other info
| Column Name | Type | Properties | Docu |
| sessionid | string:64 | Primary-Key | ID of this session, automatically generated and then stored in a cookie |
| customerid | int32 | NULL-able Foreign-Key=customer(customerid) | if logged in - the customer |
| timeout | int64 | the time when the session will be deleted, updated whenever the session is used |