Perform the user's ID processing in one function

Perform the user's ID processing in one function

There are quite a lot of options to drive the user's ID or IP address
processing, replace the ID, include or exclude the entry from the report
and so on.

That processing is only applied in full to the access.log. The redirector
and dansguardian logs are much more primitive in comparison.

By moving the processing to one function, I intent to use it everywhere.