Some users report that DAWN sometimes crashes after a while. Mostly
this happens after the new update has been rolled out.

Since I would not like to go back to the older version, I add as
a workaround for now that DAWN automatically respawned.

Workaround for:
https://github.com/berlin-open-wireless-lab/DAWN/issues/151

Signed-off-by: Nick Hainke <vincent@systemli.org>

Includes:
- dawn_uci: fix crashing when uci config is received
- tcpsocket: add option to add server ip

A new config option allows to add a server ip
	option server_ip '10.0.0.2'

However, this server does not send anything back. Therefore it is not
possible to change the node configuration. This will probably be added
soon. The main goal of this commit is to allow monitoring of all nodes
in a network with DAWN, e.g. clients, channel utilization, ...

Also a network option (3) has been added which allows to use TCP but
not to announce your daemon in the broadcast domain. This allows you to
create a monitor-only node that holds only the local information and
forwards it to the central server.

A monitor-only node could be configured like
	option server_ip '10.0.0.1'
	option tcp_port '1026'
	option network_option '3'

Another possible config is
        option server_ip '10.0.0.1'
        option tcp_port '1026'
        option network_option '2'
Here, the node shares information with a central server, which can be
located outside the broadcast domain. Nevertheless, it also shares
information within its broadcast domain and can therefore perform
client steering.

Signed-off-by: Nick Hainke <vincent@systemli.org>

DAWN has a race condition with umdns that prevents dawn from surviving
a reboot.
Increase procd start and stop of dawn to 81.

Further, network is sometimes not ready. Add utimer to check if socket
binds correctly.

Signed-off-by: Nick Hainke <vincent@systemli.org>

Dawn is a decentralized WiFi controller.
Just install dawn and the APs will find each other via umdns.
They periodically exchange information about connected clients, wireless
statistics and other needed information. With that, the daemon load
balances clients between different APs through association control.

Further, the daemon exposes through ubus the hearing map and the
complete wireless network overview. The hearing map is the list of all
probe requests seen from a client from all APs that are running the
controller.

Hearing map:
ubus call dawn get_hearing_map

Network overview:
ubus call dawn get_network

Dawn has a graphical user interface called luci-app-dawn. With that, the
load balancing and other useful settings can be controlled.

Signed-off-by: Nick Hainke <vincent@systemli.org>