The ssu CLI has been non-RnD specific for ages, get rid
of some more legacy stuff

New package ssu-network-proxy-plugin provides ssu-network-proxy,
which is required by ssu.
Signed-off-by: Juha Kallioinen <juha.kallioinen@jolla.com>

Added ssu-repos.sh tool that currently has option to cleanup /etc/zypp/repos.d/ for repositories that are not included in any rpm packages.
Signed-off-by: Marko Saukko <marko.saukko@jollamobile.com>