* Add SABAYON_EXTRA_PKGS variable for add custom
packages on building without review specs file
(for development tests)
* add option --only-dev
* integrate installation of enman repositories.
Currently this operation is done on sources chroot.
To move as plugin of molecule.
* add option for unmasking of packages through
SABAYON_UNMASK_PKGS
* Add option --skip-docker-rmi
Geaaru