No progress indication for long-running jobs

[antonio-romero-mule]

When doing a longrunning extract it's easy to become concerned that ga2CSV has failed or is otherwise just idling. It would be a big step up if e.g. there were output to stdout showing progress on an extract process- for example, if ga2csv has to make 20 requests to get through all pages of results from a query, writing "getting page N of M" to stdout or even stderr would give the user a way to know how far ga2csv has gotten.