Add debian build

[russdill]

This adds a debian build for DAWN.

This relies on the recent debian/ packaging additions to libubox and ubus as
well as pull requests for packaging of libuci, iwinfo, and rpcd:

openwrt/uci#9
openwrt/iwinfo#28
openwrt/rpcd#20

This is currently for proof of concept and experimentation, as the debian
package of hostapd does not contain any of the ubus endpoints.

[PolynomialDivision]

Can you give me some background information why adding a debian system? I'm just interested what are you planing with running DAWN on a debian system? :)

[russdill]

I'd really like to start getting some upstreaming done with the work coming out of the openwrt community. I noticed that both libubox and ubus have recently added debian packaging. The biggest impediment to running DAWN (or usteer) right now on debian is the lack ubus endpoints within hostapd.

I'd like to try and get the minimal possible changes into hostapd for allowing a rpcd-mod-hostapd shim to provide those endpoints without actually integrating ubus itself into hostapd, as that probably isn't upstreamable.

It'd also be good platform for trying to switch over some of these utilities from ubus to varlink, as ubus has some pretty big limitations.

[stokito]

This is great intention. I attempted to debianize OpenWrt https://launchpad.net/openwrt
I'll review and test your PRs and will deploy to the PPA.