Tools/scripts/report-outdated-for-maintainer.py: Update

It collects outdatedness info and presents it in many different ways
in different tables.

'Outdatedness Analysis' is the table that shows how many
ports are outdated for more than a week, month, etc.

The number of ports outdated for more than 1 month should be taken
as a measure of outdatedness for a maintainer.

Use of the portscout data in addition to Repology and GitHub is
coming up.