* Merge with Debian unstable. Remaining Ubuntu changes: - debian/prerm: Abort package removal if there is no root password. (Debian #451241). - debian/rules: Disable lecture, enable tty_tickets by default. (Ubuntu specific) - Add debian/sudo_root.8: Explanation of root handling through sudo. Install it in debian/rules. (Ubuntu specific) - sudo.c: If the user successfully authenticated and he is in the 'admin' group, then create a stamp ~/.sudo_as_admin_successful. Our default bash profile checks for this and displays a short intro about sudo if the flag is not present. (Ubuntu specific) * sudo.c, parse.c: Apply a change that was missing from the older upstream tarball that fixes the upstream solution of "SETENV is implicit for ALL". We do not want to deviate our orig.tar.gz from Debian's, though.