finetuning: fix behaviour of ln with absolut paths

the prefix inside the initvm should not be added to the symlink

Signed-off-by: Manuel Traut <manut@linutronix.de>
elbe updated: fix subcommand name in help text

Signed-off-by: Manuel Traut <manut@linutronix.de>
updated: always initialize nosign variable

Signed-off-by: Manuel Traut <manut@linutronix.de>
distinguish between pkg-list for buildenv and target

don't install packages that are specified for the buildenv into the target.

the buildenv contains both package sets.

Signed-off-by: Manuel Traut <manut@linutronix.de>