ufp: add a device fingerprinting daemon

[John Crispin]

Hi,

I posted a PR today that adds device fingerprinting.
--> https://github.com/openwrt/openwrt/pull/16568 2 
<https://github.com/openwrt/openwrt/pull/16568>
couple of folks already tested it successfully.
would be grateful if others could also give it a spin and let me know 
what they think.
please read the patch descriptions carefully, the .config needs to be 
setup correctly for it to work properly, as in

  *

    needs a BPF toolchain

  *

    needs umdns

  *

    needs the full version of wpad, the basic version does not enable
    CONFIG_TAXONOMY

    John