bb.org: cleanup /root/tmp

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
bb.org: add xinput_calibrator (NEEDS deb pkg)

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
bb.org: lightdm: start xinput_calibrator_pointercal.sh script

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
bb.org: slim: drop

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>