Add support for Debian/Ubuntu

[sbivol]

This adds support for running cake-autorate on Debian and related distributions.

I have been running cake-autorate on Ubuntu Server for a year and am willing to maintain support for this OS family going forward.

[lynxthecat]

Nice to add support for more use cases, but cake-autorate itself should not instantiate cake instances. That should be taken care of independently of cake-autorate. cake-autorate should just change the bandwidth of existing cake instances.

[sbivol]

The challenge is in there not being an easy way to get cake set up outside router-oriented distributions.
I can move ifb-setup.sh to a separate repo and reference it in the documentation.
What are your thoughts?

[lynxthecat]

Sounds good. I think that was also just recently done for another such PR.

[lynxthecat]

@sbivol shall I keep this PR open?

[sbivol]

Please keep this PR open, I have split ifb-setup.sh into its own repo at https://github.com/sbivol/cake-on-wan and am still testing it.
The next steps are to add documentation to that repo and update this PR accordingly.

[sbivol]

The changes are now in place, please review again.

[rany2]

This is what I am using:

[Unit]
Description=cake-autorate for %I
BindsTo=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device

[Service]
AmbientCapabilities=CAP_NET_ADMIN
AmbientCapabilities=CAP_NET_RAW
CapabilityBoundingSet=CAP_NET_ADMIN
CapabilityBoundingSet=CAP_NET_RAW
ExecStart=%%PREFIX/cake-autorate %%CONFIG/config.%I.sh
NoNewPrivileges=true
PrivateTmp=true
ProtectHome=true
ProtectSystem=strict
Restart=on-failure
RestartSec=5
RestrictAddressFamilies=AF_INET
RestrictAddressFamilies=AF_INET6
RestrictAddressFamilies=AF_NETLINK
RestrictAddressFamilies=AF_UNIX
RuntimeDirectory=cake-autorate

[Install]
WantedBy=multi-user.target

I would avoid using the launcher.

[rany2]

I also added d2ff9aa which should better accommodate systemd.