Logging downloads (for Seb, Pete etc).

Logging full package name in order to make it easier to identify where logs are coming from (sorry @dnahodil, I know you like having aligned log messages but I'd prefer to include all the info in the log in this case - happy to talk about this on your return).

Note also - I've disabled "timed" ajax logs as it seemed to be a bit buggy.  If and when the logs start placing too much load on the server (unlikely, IMO), then maybe we can think about re-introducing it.

@pblain it should be noted that what we've got now still won't be visible to Seb.  Probably, we need to elevate introducing something like logstash/graylog up the list of priorities if "business analyst" types users are going to want visibility in to our logs (which I think is a good thing to have, btw).