* Use stabdard python's logging lib.
* Log http-request/response/errors.
* Cmd-line options for logging-format and filename.
* Cmd-line options for request /response/error requests/responses/errors
props to log.
* Add `-v` option controlling verbosity.
* Add docs about new options.
* TCs only `-v` & `--log_file ` (logging statements used throughout all
tests).
The fix in commit 7f97612 for supporting the package naming used by the
pytz module caused a regression if the package name contained a dash
followed by a number. We fix this by splitting on all dashes followed by
numbers and recreating the package name from all components but the
last.
instead we use an iterator that returns all relevant information. that
simplifies the code quite a bit because we now mostly operate on the
iterators result instead of handling filenames, versions, prefixes...
