GDPR support for EU states

[lucliscio]

• Anonymize ip addresses²

make access to statistics more secure:

• make login mandatory
• introduce the captcha
• remove the curtain with the list of counters
• introduce robot.txt

Rif

1. https://support.google.com/analytics/topic/2919631?hl=it&ref_topic=1008008
2. https://support.google.com/analytics/answer/2763052?hl=it
3. https://support.google.com/analytics/answer/9976101?hl=it&ref_topic=2919631