[OE-core] [PATCH v2] resolvconf: add fixes for busybox and make it work

[Diego]

> resolvconf was missing a script and needed readlink which was in
> /usr/bin.  Also the /etc/resolv.conf was not being correctly linked
> to /etc/resolvconf/run/resolv.conf, which is fixed by the volaties
> change which is now a file as opposed to created in do_install.
> 
> Ensure that the correct scripts for ifup/ifdown get installed and that
> resolvconf is correctly enabled at startup

Hi Saul,

Works for me both with udhcp and static configuration, you can add:
Tested-by: Diego Rondini <diego.ml at zoho.com>

Will you be able to backport it to dizzy?

Bests,
Diego