display specific host statistics in main page

also fix a bug with urls in logs
[FIX] ignore build without hosts for displayed stats
[FIX] runbot: do not run odoo in with log-level=debug
[FIX] runbot: remove filestore when droping database
[FIX] runbot: connect to sql-db via uri
[IMP] runbot: allow grouping by host. graph view by default
[IMP] runbot: remove uneeded class (design)
[FIX] runbot: grep the correct file
[FIX] runbot: correct sql-db uri generation
[MERGE] Merge from odoo/odoo-extra d084e92b8c
[REF] Removing environ. Make errors with pylint into 8.0