unattended-upgrades: Base config on current from jessie (0.82.7)

This also replaces the old syntax "OO AA" with o=OO, a=AA
unattended-upgrades: Use better Origins-Pattern
unattended-upgrades: Enable -updates (ex "volatile")
unattended-upgrades (<< 0.70) doesn't support Origins-Pattern
Merge pull request #41 from sathieu/for_upstream

Improve unattended-upgrade on Debian