[MERGE] forward port of branch saas-4 up to 5087612d

addons/account/account_invoice.py

addons/account/views/report_agedpartnerbalance.xml

...ns/account_analytic_analysis/account_analytic_analysis.py

addons/account_voucher/voucher_sales_purchase_view.xml

addons/auth_crypt/auth_crypt.py

addons/auth_oauth/controllers/main.py

addons/calendar/static/src/js/base_calendar.js

addons/event/report/report_event_registration.py

addons/event/static/src/css/event.css

addons/gamification/models/challenge.py

addons/google_calendar/google_calendar.py

addons/hr/hr.py

addons/hr/hr_view.xml

addons/hr_holidays/hr_holidays.py

addons/l10n_be_invoice_bba/invoice.py

addons/mail/mail_thread.py

addons/mrp/mrp.py

addons/project/project_demo.xml

addons/web/static/src/css/base.css

addons/web/static/src/css/base.sass