Add "console" attribute to hardware structure

Allow the modelling of different types of OOB access to the hardware,
including support for serial consoles as well as various types of
network-based access.
AII server config: remove obsolete cdb-sync (no longer needed)
AII server: adjust default RPM configuration
- Install createrepo by default
- variable AIISERVER_INSTALL_YUM_TOOLS can be used to disable it
- Fixes #51