bin.xml assembly changes/improvements:

- add more directories (etc, sbin, bin)
- Make the paths in the tar file relative to / to allow to include /etc

This change is needed for the tar file to be useful with something else than configuration modules. For components like `ncm-cdispd`, `ncm-ncd` the tar file is missing the main pieces... Also daemons tend to need some configuration in `/etc`, something not possible with the current `bin.xml` assembly as paths in the tar file were related to `/usr`.