* Remove XFrame header set in \WebPage::no_cache : not this method responsability, was confusing :/
* Remove no_cache() calls when already set in page constructor (ajax_page mainly)
* Also calls everywhere the \WebPage::no_cache method instead of setting headers manually
* Add CLI command bin/report.php to generate report offline
* Keep the latest report in log/dbtools-report.log in order to visualize it with "Log management" menu