* merge from ubuntu: * make cache calculations quicker (thanks to Ben Hutchings, closes #475610) * add hostname in mail header, thanks to Arthur de Jong (closes: #502171, LP: #245417) * better email summary of the performed actions (closes: #502351) * be more robust against failures to read the deb (LP: #227448) * better debconf template and description (thanks to the debian-l10 team (closes: #508136) * debian/po/sv.po: - add sv.po debian template (closes: #508225) * debian/po/it.po: - add it.po debian template (closes: #508193) * debian/po/ja.po: - add ja.po debian template (closes: #508564) * debian/po/de.po: - add de.po debian template (closes: #508481) * po/fr.po: - add fr.po translation (closes: #508390) * po/cs.po: - add cs.po translation (closes: #508702) * po/pt.po: - add pt.po translation (closes: #508705) * unattended-upgrade: - better default permissions of the install log (closes: #507638) - only disable apt-listchanges if it is not set to 'mail' (closes: #507639)